JP2005503864A - Impedance-controlled tissue peeling device and method - Google Patents

Abstract

A method and apparatus for carrying our thermal ablation of target tissue is disclosed. The apparatus includes an RF ablation device having a multi-electrode electrode assembly designed to be deployed in target tissue, defining a selected-volume tissue region to be ablated, and having infusion channels for infusing a liquid into the target tissue during the ablation process. A control unit in the apparatus is operably connected to an RF energy source, for controlling the RF power level supplied to the electrodes, and to an infusion device, for controlling the rate of infusion of a liquid through the device into the tissue. During both electrode deployment and tissue ablation, impedance and or temperature measurements made within the tissue are used to control the RF source and infusion device, for optimizing the time and extent of tissue ablation.

Description

【Technical field】
[0001]
(Field of Invention)
The present invention generally relates to a method for treating tissue using a method that is minimally invasive. More particularly, the present invention relates to an apparatus and method for exfoliating tumor tissue and diseased tissue. Even more specifically, the present invention relates to an apparatus and method for ablation treatment of tumor tissue that uses impedance values to control and optimize the delivery of electromagnetic ablation energy to a target tissue site.
[Background]
[0002]
(Background of the Invention)
Various ablation therapies (eg radio frequency ablation, microwave ablation and laser ablation) can be used to treat benign and cancerous tumors. In theory, such methods are intended to produce physiological and structural changes to cause cell necrosis or cell destruction of selected target tissues. In practice, however, there are a number of problems in the use of ablation procedures to treat cancer tissue, including: (i) locating the target tissue, (ii) tumor Identifying the disease state of the tissue or performing a biopsy; (iii) distinguishing between diseased tissue and healthy tissue; (iii) placing and maintaining the position of the ablation device within the target tissue site; (iv) ) Monitoring the progress of detachment, including the expanding detachment volume, (v) minimizing damage to adjacent critical structures, (vi) complete detachment of the tumor mass, including compensation of sufficient room for healthy tissue And (vii) assessment of the degree of complete delamination. Current exfoliation treatment has not considered or provided an answer to these problems. Thus, there is a need for devices and methods that address these issues, as well as a need that has not yet been explored in performing exfoliation therapy for the treatment of cancer, tumors, and other diseases.
DISCLOSURE OF THE INVENTION
[Means for Solving the Problems]
[0003]
(Summary of the Invention)
Embodiments of the present invention provide impedance controlled tissue ablation devices and methods that optimize impedance delivery methods (e.g., radio frequency or other electromagnetic energy delivery to a target tissue site, lower power levels and Use local tissue impedance (using a faster ablation time to create a larger ablation volume than is currently possible using conventional RF tissue ablation techniques). By reducing the power level required to create an ablation volume, the device also benefits significantly reducing the risk of pad burns and other electric shock accidents associated with conventional RF ablation therapy. I will provide a. A related embodiment of the present invention uses controlled infusion of electrolyte fluid at the tissue site to control and maintain tissue impedance at an optimal level of delivery of ablation energy.
[0004]
Another embodiment of the invention provides an apparatus for detecting and treating tumors using localized impedance measurement methods. The apparatus includes an elongated delivery device that includes a lumen and is easy to manipulate in tissue. The impedance sensor array can be deployed from an elongate delivery device and is arranged to be coupled to at least one of an electromagnetic energy source or a switching device. The impedance array comprises a plurality of elastic members, at least one of the plurality of elastic members can be disposed in a compacted manner in the elongated delivery device, and in the deployed state, tissue from the elongated delivery device. Can be curved inward and deployed. In the deployed state, the plurality of elastic members define a sample volume. At least one of the plurality of elastic members includes a sensor, and at least a portion of the impedance array is configured to sample tissue impedance by the plurality of conductive paths. The energy delivery device is coupled to one of a sensor array, an elastic member or an elongate delivery device.
[0005]
Embodiments of the present invention provide methods for detecting and treating tumors using tissue localized volumetric impedance measurements. The method includes providing an impedance measurement device having an elastic member that is curved and deployable and configured to sample tissue impedance by a plurality of conductive paths. The apparatus is configured to be coupled to at least one of an energy delivery device, a power source, a switching device, or a logical resource. The device is then placed at the selected tissue site and the impedance array is deployed to define the sample volume. The impedance array is then used to perform an impedance measurement method with a plurality of conductive paths. Information from the impedance measurement method is then used to determine the tissue condition of this sample volume. Energy is then delivered from the energy delivery device to ablate or necrotize at least a portion of the tumor.
[0006]
The device is configured to detect, locate and identify tumor tissue at a selected tissue site using impedance measurement methods (eg, multipathing impedance determination method, composite impedance determination method and impedance vector determination method). obtain. For complex impedance embodiments, the real and complex components of the impedance signal provide finer bioelectrical parameters (e.g., interstitial impedance and intracellularity) that provide greater susceptibility and predictability of cell necrosis or malignancy. Impedance as well as cell membrane capacitance). The device also includes one or more impedance determination methods that monitor the target tissue site and control the process of exfoliation therapy before, during, or after delivery of ablation energy or other treatment to the tissue site. Can be configured for use. Thus, the device is configured to be used independently or in combination with another stripping device (eg, RF, microwave laser or other optical stripping device). In addition, the device can be configured to use a multipath impedance measurement method to monitor two or more tissue volumes including tumor volume, expanding exfoliation volume and adjacent anatomical structures. Further embodiments of the apparatus also use impedance determination methods (eg, composite impedance determination method, vector impedance determination method or position impedance determination method) to generate images of target tissue sites, placement and tumor volume and / or ablation Displays an image to facilitate volume monitoring.
[0007]
In use, the device is placed at a selected tissue site that has been previously imaged and found to contain a tumor mass or other tissue mass. The apparatus is introduced and placed at a tissue site using an elongate delivery device or by introducing a device known in the art, such as a trocar or endoscopic device. The impedance array is then deployed and used to determine the impedance including complex impedance and capacitance by one or more conductive paths. This information can be analyzed by the combined logic source and used to locate the location and boundaries of the tumor volume and / or to identify the tumor type or tissue type. Information is also processed by logic sources or other processing means, using impedance location in a way that indicates the center of the tumor mass or otherwise visually enhances the detection and display of the tumor mass An image of a tissue site that includes a tumor volume may be generated. This information can then be used to locate the energy delivery and obtain the desired peel volume. Once the energy delivery device is positioned, the impedance array can be used for monitoring and / or controlling the delivery energy or treatment delivery to the tumor volume, which is related to the size and position of the tumor volume. Monitoring the size and shape of the expanding peel volume. This not only allows the practitioner to determine the extent to which the tumor volume has been ablated, but also allows control of the amount of room for healthy tissue around the tumor volume. Such control and associated capabilities allow the determination of the desired clinical endpoint. In addition, this allows the practitioner to titrate or otherwise control the delivery of energy or other ablation therapy, the rate of increase of the exfoliation volume (and then the overall exfoliation time) as well as the final volume of the tumor Control shape and size. Multiple tissue volumes are monitored in real time to monitor the increase in exfoliation volume, to ensure uniform resection or necrosis across the tumor volume or exfoliation volume, and that the surrounding healthy tissue and structures have not been damaged. Can be monitored and compared at the same time to assure. For example, the tissue volume at the center of the tumor mass and around one or more can be monitored simultaneously or nearly simultaneously to ensure uniform necrosis across these locations and thus the tumor volume. Impedance determination methods are determined simultaneously or sequentially in a number of conductive paths through the target volume (convergence and divergence and paths), as well as any measurement directional deviations. Reducing the size of the unsampled area within the volume can provide higher reliability of uniform delamination. Many conductive paths can be electrically selected by a controllable switching device or manually selected by rotational, lateral or longitudinal movement of an impedance array within the target volume. In the former case, the user can program the conductive path with a coupled monitoring device, in the latter case, the user can use an elongate delivery device or deployment device, advancement mechanically coupled to an impedance array or delivery device. The impedance array can be rotated, advanced, retracted or deflected by the device or the deflection device. In addition to the real-time impedance determination method during the stripping process, measurements can be taken after stripping in one or more paths (including paths different from those used during stripping monitoring) and baseline Measurements or compared to an impedance database may provide further indication of complete delamination and / or clinical endpoint. The endpoint can also be determined based on the ratio of intracellular impedance to interstitial impedance and the characteristic shape of the impedance curve or composite impedance curve (including determination of threshold, slope or inflection point).
[0008]
Various aspects of the invention may also relate to showing impedance determination methods in various ways that are both manageable and easily recognizable by the user / practitioner. In one embodiment, the location of the sample volume impedance or the impedance vector of the sample volume may be shown as an icon to facilitate tumor identification and placement of an energy delivery device or ablation device within the tumor mass. In a related embodiment, the logic source of the apparatus uses impedance vector measurements to determine the radial direction of the tumor from the impedance array or energy delivery device and indicates this information in the form of a direction icon or indicator icon Can be configured as follows.
[0009]
(Detailed explanation)
(Definition)
The following terms as used herein have the following meanings unless otherwise indicated:
“Electrode”, “resilient member” and “antenna” are interchangeable, and these refer to a needle or wire for conducting energy to a tissue site. The electrodes are passive, active, or switchable (switchable) between passive or active. Further, the electrode can be a ground pad electrode that can be positioned at an external location of the patient.
[0010]
A “sensing member” is a passive electrode or an active electrode for sensing an ablation parameter.
[0011]
“Fluid delivery device” and “infusion device” are interchangeable and are they connected to (i) a source of fluid to be infused, and (ii) one or more electrodes? Or a device comprising them, or an elongated delivery device for delivery of fluid to a target site.
[0012]
"Feedback control device", "control unit (control unit)" (control unit), "control resource", "feedback control system", and "control device (controller)" (controller) are interchangeable And a controller that can adjust the stripping parameters (ie, power, temperature, injection, etc.). This control can be operated automatically or manually.
[0013]
“Impedance measurement” or “impedance determination” can be interchangeable and using any suitable computing device or algorithm known in the art, the data source (ie, current sensor, voltage sensor, Or calculating the impedance from the power supply).
[0014]
Embodiments of the present invention provide local impedance determination (complexity) for positioning and diagnosing a tumor, accurately positioning the ablation device, monitoring the progress of the ablation procedure, and determining the clinical endpoint. Devices and methods for performing tissue characterization using impedance determination (including impedance determination) are provided. Furthermore, these and other embodiments of the present invention can be arranged to measure and analyze bioelectric parameters using the enhanced predictable power of cellular metabolites, along with associated images, This measurement and analysis allows real-time control of the ablation process while significantly reducing the risk of incomplete ablation or unwanted loss to the clinical anatomy. Each of the disclosed embodiments may be considered individually or in conjunction with other variations and aspects of the invention. The methods and devices provided herein are for cancerous tumors in whole organs and tissues of the body, including but not limited to liver, bone, breast, lung, and brain. Useful in treatment. They are also useful and equally applicable for the treatment of benign tumors, growth and other abnormal or enlarged tissues that require removal, excision or modification by surgical or minimally invasive means .
[0015]
The local monitoring of impedance provided in various aspects of the present invention is particularly advantageous for use in the treatment of tumors and tumor tissue with ablation therapy (eg, RF, microwave, laser and chemical ablation). These and related exfoliation treatments cause destruction of the cell membrane, resulting in a change in interstitial fluid impedance, but with minimal or no change only in the affected tissue compared to the surrounding tissue. Previous attempts to determine impedance using a complete electrical circuit through the patient's body had the disadvantage that the local impedance of the tissue could not be detected by not considering the issues involved. These issues include the following:
(I) related to the impedance of the entire impedance determination system (conducting path through the body, ground pad electrode and associated wires) and / or shielded by this impedance, the signal is very small:
(Ii) measurements are made on the body very far from the desired tissue site and are therefore also shielded; and
(Iii) Local impedance was shielded by RF or other ablation energy signals delivered to the tissue.
Embodiments of the present invention provide a solution to these problems, where local impedance changes (especially changes that occur during an ablation procedure) are detected by the use of an impedance array located in the target tissue, and complex impedances are provided. And other bioelectrochemical properties described herein.
[0016]
Here, a discussion of impedance determination theory and impedance determination methods used by embodiments of the present invention is provided. Current is applied across the tissue and the resulting voltage is measured for the purpose of determining tissue impedance or impedance (which typically has units of impedance / cc of tissue at 20 ° C.) . This current (known as the excitation current or excitation signal) is relatively small compared to the stripping RF or other stripping current and therefore does not produce a perceptible stripping effect. In various embodiments, the excitation current can range from 0.01 ma to 100 amp, with specific embodiments being 0.1 amp, 1.0 amp and 10 amp, in a continuous manner or using a duty cycle Can be delivered in a pulsed manner. In various embodiments, the duty cycle can range from 5-50% with a pulse duration of 10-200 ms. The average power delivered over the course of the duty cycle can range from 0.1 to 10 watts. In these and related embodiments, an excitation current source is used to measure the voltage difference between two or more sites in a bipolar manner, or between one or more sites and a common ground. . The known excitation current and measured voltage are then used to derive the impedance using algorithms and methods described herein and / or known in the art.
[0017]
Because different frequencies conduct differently through different tissue types, either tissue is more conductive or less conductive at a particular frequency. Thus, depending on the tissue type or condition to be detected, the sensing or excitation signal can be varied or otherwise controlled to provide one or more of the sensitivity, accuracy, precision and resolution of impedance determination. Can improve. In various embodiments, the excitation signal can be a single frequency signal or a multi-frequency signal and can be constant or variable. In one embodiment, improved signal resolution and thus more accurate tissue analysis and characterization may be achieved through the use of multi-frequency excitation signals and / or excitation signals that vary over a wide range of frequencies. In various embodiments, this frequency range can be from about 1 Hz to about 1 MHz, with specific embodiments being 0.5 Hz, 1 kHz, 5 kHz, 10 kHz, 25 kHz, 50 kHz, 100 kHz, 250 kHz, 500 kHz, and 750 kHz. . Since the bioelectrical difference (eg, phase angle, impedance) between cancer tissue and healthy tissue can be greatest at low frequencies such as 100 Hz, in an exemplary embodiment, measurements are made at multiples below 100 Hz. Specific embodiments are three, four, ten, and twenty frequencies below 100 Hz. Other embodiments may combine measurements at less than 100 Hz with measurements between 100 Hz and 5 kHz.
[0018]
Further embodiments of the invention can be constructed to determine impedance at different excitation frequencies (either simultaneously or sequentially) to obtain more robust data and thus more sophisticated clinical diagnostic information. Using these and other data and methods, as described more fully herein, impedance vs. frequency plots can be generated and analyzed for sampled tissue volume to obtain sample volume tissue. The mold and tissue status can be determined.
[0019]
Complex impedance includes both real and imaginary components, which reflect the phase shift between voltage and current (eg, voltage depends on the electrical properties of the tissue, Can lead or delay). Various embodiments of the present invention may be configured to record both real and imaginary component of complex impedance. This offers the advantage of providing more comprehensive information about the tissue and allows analysis with a greater degree of accuracy, precision and resolution. These components are determined by flowing the excitation current through the target tissue and determining the impedance and / or any phase shift between current and voltage when the signal conducts through the target tissue. obtain.
[0020]
In related embodiments, the real and imaginary components of impedance can be used to determine intracellular impedance, interstitial impedance, and cell membrane capacitance. These three elements can be used alone or in combination to uniquely characterize and identify tissue types and conditions with increased amounts of precision. In one embodiment, the monitoring device or other logic resource utilizes these three parameters (“three parameters”) to perform a stripping procedure (eg, RF stripping or the stripping method described herein). Can be configured to characterize the amount of exfoliation or the progress of tissue exfoliation. Characterization can be done by software modules that reside on the monitoring device, power supplies, and coupled logical resources, all of which are described herein.
[0021]
In certain embodiments, the three parameters are indicated by various physiological indicators of detachment and cell necrosis (cell lysis, cell membrane swelling (indicated by an increase in membrane capacitance), cell membrane twist (abrupt decrease in membrane capacitance). ), A decrease in extracellular fluid (indicated by an increase in intracellular impedance) and an increase in intracellular fluid (indicated by a decrease in extracellular fluid). Other parameters that can be calculated and used for detection and control purposes include: absolute value of impedance or admittance, phase of impedance (eg, phase difference between current and voltage), capacitance, or impedance component and admittance A combination function with a component can be mentioned.
[0022]
Particular embodiments of the present invention provide an increase or decrease threshold (1.1: 1.0 to 100: 1.0 in the range of one or more of the three parameters (or other variables) or And specific embodiments are 1.5: 1.0, 2: 1, 3: 1, 4: 1, 5: 1, 10: 1, 20: 1, and 50:10). May be configured to be detected and / or controlled. Related embodiments may be configured to obtain and / or control a combination of increases or decreases in parameters including the following: an increase and subsequent decrease in extracellular impedance, a decrease and subsequent increase in intracellular impedance, and a cell membrane Increase in capacitance and subsequent decrease. Other related embodiments may be configured to detect, monitor and control changes in the slope of one or more of the three parameters. Still other related embodiments may use PID control methods known in the art that utilize a combination of proportional, integral or derivative changes of the three parameter curves.
[0023]
Embodiments of the present invention may incorporate three parameters into an electronic algorithm / software program that is configured to perform one or more of the following: (i) power to the target tissue site (Ii) provide the medical practitioner with prompts and diagnostic information about the progress of the ablation / treatment process, and (iii) provide the medical practitioner with indications of clinical endpoints.
[0024]
Referring now to the drawings, FIG. 1 shows an embodiment of an impedance monitoring and treatment device 10, which samples the impedance of a tissue mass and delivers energy or other ablation procedures to provide an ablation volume 5av. Is configured to detect and treat a tumor mass 5 ″ at the target tissue site 5 ′. This device determines impedance (including complex impedance) before, during and after exfoliation. This can be configured to perform tissue identification at the target site, monitor the progress of the ablation procedure (including the increasing ablation volume), and qualitatively determine the clinical endpoint of the procedure.
[0025]
Referring now to FIGS. 1 and 2, an embodiment of the impedance treatment device 10 includes a lumen 13, a proximal portion 14, a distal end 16, one or more elastic members 18 (which are within the introducer lumen 13. And one or more sensors 22 (which can be disposed on the member 18) or sensing members 22m (which can be disposed within the electrode lumen 72 disposed within the member 18). An elongated member or introducer 12. The electrode distal end may be sharp enough to puncture tissue, including fibrous and / or encapsulated tumor masses, bones, cartilage and muscles. Introducer lumen 13 may extend all or part of the length of introducer 12. The member 18 may comprise a plurality of 18 pl elastic members 18 that can be placed in the lumen 13 and can be distant by advancement of the device 15 or advancement member or other means described herein. Configured to be advanceable into and out of the distal end 16. The elastic member 18 can be deployed with curvature from the introducer 12 to collectively define a volume 5av at the target tissue site 5 '. In certain embodiments, all or a portion of the one or more members 18 can be an energy delivery device or energy delivery member as described herein. The energy delivery device 18e may be coupled to an energy source or power source 20 and may also include one or more lumens 72.
[0026]
Embodiments of the present invention include multiple ablation treatments (high frequency (RF) ablation, low temperature ablation, brachytherapy, alcohol tissue ablation, chemical ablation, microwave ablation, laser ablation, thermal ablation, electroporation ablation, conformal (Including, but not limited to, beam radiation ablation, standard radiation ablation, high intensity focused ultrasound ablation, photodynamic therapy ablation) can be adapted, integrated, and otherwise applicable. These and related embodiments may comprise an energy delivery device and a sensing device coupled to a power source.
[0027]
For ease of discussion, the energy delivery and sensing device is an RF-based device and the power source 20 is an RF power source; however, all other embodiments discussed herein include: Is equally applicable. In certain embodiments, the RF power supply delivers a treatment current 20t for tissue ablation and uses (multiple and / or switching devices) to perform complex impedance determination and subsequent analysis of the target tissue at or near the same time. And) may be an RF generator configured to deliver a low power sensing or excitation signal 20e over one or more frequencies. Excitation signal 20e can be delivered over a wide band of frequencies in the range of 1-1 MHz. In various embodiments, an excitation signal is delivered at a low frequency and then a treatment signal (typically 460 ± 60 kHz) is delivered. In certain embodiments, the excitation signal is less than 400 kHz. In other embodiments, the sensing signal ranges from 1 h to 100 kHz, and specific embodiments are 0.25 kHz, 0.5 kHz, 1 kHz, 5 kHz, 10 kHz, 25 kHz, 50 kHz, and 75 kHz. In an alternative embodiment, the excitation signal is delivered at a higher frequency than the treatment frequency and can therefore be greater than 520 kHz. In addition, frequency and power differences between the excitation signal 20e and the treatment signal 20t can be monitored, and certain points can be controlled using circuit structures and control algorithms known in the art. Also, the frequency and power differences between these two signals are changed in response to one or more electrical parameters to maximize the accuracy and precision of the impedance determination and to interfere with the treatment signal 20t (eg, , Bleeding) can be reduced. These electrical parameters include, but are not limited to, impedance, treatment current, treatment frequency, excitation current, and excitation frequency.
[0028]
In various embodiments, the introducer 12 can be flexible, articulated and steerable, and includes optical fibers (both illumination and imaging fibers), fluid and gas paths, and sensors and electrical cables. Can be prepared. In one embodiment, introducer 12 may be configured to pierce tissue and also be steerable within tissue. This can be accomplished by use of a flexible portion coupled to the tissue piercing distal end 16 (which can be a needle or trocar tip that is integral with or joined to the introducer 12). . Introducer 12 may be sufficiently flexible to move through tissue and into the desired tissue site 5 'in any desired direction. In a related embodiment, introducer 12 is sufficiently flexible to reverse the direction of movement and move itself back. This can be achieved through the use of flexible materials and / or deflection mechanisms as described herein. Introducer 12 may also be coupled to handle 24 or handpiece 24 at its proximal end. The handpiece 24 is removable and may include a port 24 ′ and an actuator 24 ″.
[0029]
One or more sensors 22 may be coupled to introducer 12, elastic member 18 or energy delivery device 18e. In one embodiment, the sensor 22 may comprise one or more sensing members 22m, which may be positionable within the lumen 72 of the member 18 and into and out of the individual member 18. It can be configured to be advanceable or can be coupled to the outside of the elastic member 18. The sensing member 22m may include a plurality of members 22mpl disposed in the plurality of elastic members 18. The device 10 also provides for measurement and determination of total impedance across the electrical circuit between the terminals of the power source 20 (ie, through the patient's body to the ground pad) along the elongate member 12 and at the target tissue site. May have sensors 22 located at other locations outside of. The total impedance can be monitored and otherwise utilized to improve the accuracy and precision of determining local impedance from the target site.
[0030]
An impedance sensing member 22m (ie, sensor 22) coupled to the elastic member 18 may be deployed independently or simultaneously to allow probing of the target tissue 5 'at multiple locations, thereby providing a plurality of Impedance is determined at the location and / or through the plurality of conductive paths 22cp. The deployment of the impedance sensing member 22m or sensor 22 can be controlled so that telemetry can be used with impedance feedback to identify the tissue type and to map the topography of the tissue mass, tumor or tumor structure. .
[0031]
The impedance sensing member 22m may also be disposed curved from the member 18 and collectively define a volume 5sv (also referred to as a sample volume 5sv) that is volumetrically sampled by the plurality of sensing members 22mpl. Collectively, a plurality of arranged impedance sensing members 22m (22mp) or a plurality of arranged elastic members 18 (18pl) having coupled sensors 22 may include a three-dimensional or volumetric impedance sensor array 22a. By having the sensors 22 at multiple sites and surfaces, the sensor array 22a samples the internal tissue of the target tissue site 5 ′ including the tumor mass 5 ″ by volumetric measurement (eg, at multiple sites, a plurality of conductive layers). Sampling through the sexual pathway). The sensor array 22a is further configured to allow simultaneous sampling of tissue at a volume 5sv or multiple sites within the tissue site 5 'to perform one or more of the following: (i) a tumor mass (Ii) identify the location or placement distance of the energy delivery device 18, (iii) monitor the developing exfoliation volume, (iv) two or more sites (e.g., known) Tissue sensing discrimination is performed by comparing signals between healthy tissue and suspected diseased tissue). In various embodiments, the sensor array 22a and / or the plurality of members 18pl may have various configurations (including, but not limited to, hemisphere, sphere, ellipse, cone, pyramid, polyhedron, or tetrahedron for the sample volume 5sv. ).
[0032]
Each elastic member 18 may be configured in various configurations to perform one or more impedance sensing members 22m and / or one or more desired functions described herein (eg, tissue identification, detachment monitoring, etc.). There may be a sensor 22 that may be placed. Referring now to FIG. 3a, the sensing member 22m is in bipolar between two or more members 22m or is in contact with one or more selection members 22 and a common ground (eg, ground electrode or ground pad electrode). It can be configured to determine any impedance in a unipolar manner between. Switching between the two modes can be controlled by a switching or device 29 that is connected to or integral with the logic resource and / or impedance monitoring device 19 or power source 20. Furthermore, the switching device 29 can be configured to allow a user to define and select one or more conductive paths 22cp to determine impedance. In use, and related embodiments, allow the user to select any number of 22pp styles that limit or otherwise define the conductive path and the target sample volume 5sv. The use of switching device 29 in these embodiments also allows the user to determine the impedance simultaneously or sequentially through the selected path. Further switching device 29 and / or apparatus 10 may be configured to allow a user to dynamically change and switch between paths to do one or more of the following (i)-(v): :
(I) changing the number of paths through the selected sample volume, which enhances the signal resolution and the statistical confidence of the predicted tissue condition;
(Ii) changing the angle between two or more conductive paths; and
(Iii) changing the size of the sample volume; (iv) switching between the first sample volume and the second sample volume; and (v) comparing two volumes or sample volumes simultaneously.
[0033]
In the embodiment shown in FIG. 3b, the conductive path 22cp may include an initial path and an alternative path. The alternative path may be a selectable angle from the initial path and may form a common point with the initial path. Suitable angles include 30 °, 45 °, 90 °, and 270 ° from the horizontal axis 22la of the initial path in certain embodiments, including a range of 1 ° to 360 °. Alternatively, the alternative conductive path may share one or more points in common with the original path, or may be parallel to the original path, but corrects the selectable lateral distance 22ld. Conductive repetitive scans, including sweep scans and continuous sweep scans (eg, continuous sampling from one side of the sample volume to the other, maintenance radar) can also select one or more of the selected sample volumes Over time, the time course of delamination can be monitored, as well as an improved signal to noise ratio and signal analysis capability for image analysis.
[0034]
Changes in the angle and / or lateral correction of the conductive path used to determine impedance can be achieved by a variety of means including, but not limited to: (i) selecting sensor 22 or sensing element 22m (Ii) selectively switching the sensing element 22m from a monopolar mode to a bipolar mode and vice versa (iii) rotatable using a switching device 29 (for the RF embodiment) And / or configuring the probe array to be bendable, and (iv) use and / or placement of the second array, either on the same device or on a different device. Switching can be accomplished through the use of a switching or multiplexing device 29 that can be programmable or controlled by the logical resource 19lr described herein.
[0035]
In one embodiment, data from an alternative conductive path or group of paths is combined with measurements from an initial conductive path for analytical and imaging purposes, or in an alternative embodiment, separate Can be analyzed and displayed to allow comparison of both measurements and images from the initial and alternative groups of paths. The former advantage is a more representative and uniform sample of impedance, and the latter advantage is the detectability for conductivity uniformity within the sample volume.
[0036]
In use, such embodiments sample or image a tissue volume larger than a single path sampling by a physician and sample multiple tissue volumes, including simultaneous sampling without the need for repositioning of the device or conductive array Make it possible. This capability reduces procedure time and generally increases the usefulness of the device. Furthermore, such embodiments also control the shape and size of the sample volume to sample only the region of interest excluding any potential masking or undesired impedance contributions from surrounding non-target tissues. Selecting a conductive path provides a more accurate and representative signal of the target tissue volume. The ability to switch path angles also eliminates or reduces any directional bias in impedance determination. Finally, with a larger sample size and volume distributed sample size for the desired volume of tissue, the use of multiple conductive path impedance determinations has improved the accuracy and precision of impedance determination for the selected volume, It provides a more representative measure of impedance with improved signal resolution in both the signal and all three dimensions.
[0037]
Referring now to FIGS. 4a-4c in various embodiments, the impedance sensing member 22m has various geometries for electrically sampling different volumes of tissue 5sv using different conductive paths 22cp. And can be placed in the relevant array 22a. Such an embodiment provides the benefits of improved acquisition, accuracy and analysis of the impedance signal 19p from a given sample volume 5sv, reduced signal history, noise (due to energy delivery, etc.), directionality To correct for bias or other errors. They also provide the advantage of simultaneous sampling and comparison of two or more tissue volumes, and tissue identification is performed.
[0038]
4a-4c, the conductive path 22cp can have various configurations and orientations, all selectable by the user. In certain embodiments, the conductive path 22cp may ultimately be distributed or arranged within the sample volume 5sv. This can be achieved by either or a combination of the use of switching device 29 depending on the configuration of member 22m. Alternatively, the conductive path can be arranged relative to one or more sensing members 22m, introducer or tumor volume 5 '' itself. In the embodiment shown in FIG. 4a, one member 22mc is placed in the center of the sample volume 5sv and multiple members are placed around it, so that the excitation current or impedance that is outside the center of the sample volume 5sv The sensing member 22m reciprocates in a plurality of conductive paths 22cp (22pp). In use, this configuration results in an impedance determination for the sample volume 5 sv, which is the average of the individual impedances for each conductive path, and selected tissue rather than being provided by a single path alone. Provides the advantages of statistically more representative samples of impedance with respect to volume. Member 22m is coupled together to the anode of power supply 20 with member 20 configured as a regression electrode and coupled to the return terminal of power supply 20.
[0039]
In the related embodiment shown in FIG. 4b, member 22m may be biased with respect to member 22m and / or placed around the sample volume defined by member 22m. Again, this embodiment provides the benefits of average impedance determination and more representative impedance determination for sample volumes. However, this configuration also provides the advantage of being able to more easily detect and locate the impedance non-uniformity and hence the tissue properties that occur at the tissue volume boundaries or other non-centered members. The use of the switching device 29 facilitates potential non-uniformity within the sample volume by allowing the return electrode to quickly scan different positions around the sample volume for dynamic switching of any sensing member 22m. Allows to detect and position sex.
[0040]
Alternatively, as shown in FIG. 4c, member 22m can include a first array (eg, a vertical array) and a second array. This first array is for obtaining different conductive paths to the second array to sample different tissue volumes and / or to provide multiple samplings of the same volume (via different conductive paths) , Can be rotated, the accuracy and accuracy of the measurement is improved and the noise is reduced. In use, this embodiment also includes an impedance determined from a first group of conductive paths 22cp1 defined by the first array 22a1 and a second group of conductive paths 22cp2 defined by the second array 22a2. By comparison, incomplete peeling can be detected.
[0041]
In various embodiments, the apparatus 10 utilizes different switching devices or multiplexers 29 or other switching means as described herein or known in the art, and at the same time within the target tissue site 5 '. It may be configured to sample the position. In the embodiment shown in FIG. 5, the first group of selected conductive paths 22cp ′ can be used to sample the local first volume 5sv1 and the second group of selected conductive paths 22cp ″ is A third group of conductive paths 22cp ′ selected and sampled to sample the second volume 5sv2; more or less defined by a plurality of sensor tip members 18 or sensing members 22m A large or wide sample volume 5sv3 can be selected for sampling. Each sample volume produces a separate impedance profile 19p. Thus, sample volumes 5sv1, 5sv2 and 5sv3 are respectively 19p1, 19p2 and 19p3, all or part of the profiles that can be compared to each other, or profiles using the comparison / modal recognition algorithm of module 19m (other software or calculation means) A database of impedance 19 db can be created. In a related embodiment, the impedance signal determined for each sample volume is integrated or otherwise analyzed by module 19m or other computing means, and for each individual sample volume, impedance vector 22v and impedance 22i The location (eg, impedance vectors 22vl, 22v2, 22v3; and impedance locations 22l1, 22l2, and 22l3) can be determined.
[0042]
Referring now to FIG. 6, in one embodiment, one or more sensors 22 or sensing members 22m may be connected to an impedance determination device and monitoring device 19. The monitoring device 19 includes the circuitry described herein and measures the potential from the excitation current and simultaneously calculates the impedance. Further, the monitoring device 19 also measures, calculates and calculates complex impedances, impedance profiles 19p and complex impedance profiles 19pc resulting from various tissue bioelectric properties, including impedance conductivity, capacitance, etc. Can be configured for recording. In some embodiments, the monitoring device 19 may include a logic resource 19lr (eg, a microprocessor) configured to analyze, store and display information from the tissue impedance profile 19p and / or the sensing member 22m and / or the sensing array 22a. And a memory source 19mr (eg, a RAM chip or a DRAM chip). Impedance monitoring device 19 may also be connected to display device 21 for displaying in real time or for displaying stored impedance profile images and other data generated by impedance monitoring device 19. Examples of the display device 21 include a cathode ray tube (CRT), a liquid crystal display, a plasma display, and a flat panel display. The display device 21 can also be incorporated in an external computer to which the impedance monitoring device 19 is connected.
[0043]
In various embodiments, the impedance monitoring device 19 or the power source 20 may include a number of features including, but not limited to:
(I) memory resources including a database of specific impedance profiles;
(Ii) an output window for impedance-based diagnosis of tissue type and / or condition;
(Iii) an artificial intelligence algorithm / program that can be learned from the impedance scan newly obtained by the generator;
(Iv) the ability of the user to enter and teach the correct tissue type and status based on biopsy or pathology to the generator;
(V) Ability to sense multiple frequencies of impedance simultaneously to improve speed, accuracy and reduce the effects of disturbances;
(Vi) Ability to use non-invasive pads (such as electrophysiological pads) for performing complex impedance measurements and performing non-invasive target tissue assessments;
(Vii) the ability to monitor reference signals and / or basic patient electrophysiological status for baseline comparison of impedance reading information and further information for the user; and
(Viii) using digital subtraction, digital suppression and other signal processing methods known in the art to improve signal noise ratio, signal sensitivity or signal analysis, hysteresis, signal noise, reference signal or interference and other signals Programming to use the signal that causes the failure.
[0044]
In various embodiments, the apparatus 10 can be configured with the impedance monitoring device 19 to perform tissue identification, differentiation, detachment monitoring, and tissue mass and structure mapping. In certain embodiments, monitoring device 19 is configured to perform tissue identification functions using impedance information derived from sensor 22, detection member 22m or array 22a. Here we present a discussion on the background of tissue monitoring and identification using impedance determination. Due to variations in composition and morphology, various tissue types have different electrical properties (eg, conductance, inductance, capacitance, etc.) and thus conduct electrical energy differently, particularly at specific frequencies. For example, cancerous tissue typically has a significantly higher phase than healthy tissue, particularly at low frequencies. These differences in electrical properties, particularly conductance, produce a characteristic impedance profile 19p for a given tissue type or condition when the tissue is exposed to an excitation current at one or more specific frequencies. . Impedance profile 19p may have one or more peaks, curves and other shapes that serve as a tissue type or tissue state fingerprint. Thus, by analyzing the impedance profile 19p and matching peaks, curve shapes, thresholds, etc., the profile 19p is used to identify tissue types and conditions such as malignancy, vascularity, necrosis, thermal damage, etc. Can be used according to embodiments of the present invention. Related conditions that can also be identified using this approach include abnormally mutated tissue, abnormally dividing tissue, or hypoxic tissue.
[0045]
In addition, many tissue types, including cancerous tissue such as metastatic tissue, can be easily identified using pattern recognition techniques or algorithms known in the art and matched to a database of profiles. Has a profile 19p. Accordingly, the apparatus 10 analyzes an impedance profile 19p that includes real and imaginary components and a monitoring device 19 configured to perform tissue identification and / or tissue differentiation between one or more sampled volumes 5sv. May include an electronic algorithm or software module 19m that resides in a logical resource 19lr or a micro processor 339. Module 19m may include pattern recognition algorithms, curve fitting, fuzzy logic, or other numerical analysis methods known in the art. Also, in one embodiment, module 19m compares profile 19p with a database of profiles 19db stored in memory resource 19mr to indicate a correlation coefficient or statistic that indicates a possible match for a given tissue type or condition ( For example, it may be configured to use curve fitting and other numerical analysis methods known in the art to provide and display the p-value).
[0046]
In various embodiments, impedance and other bioelectric properties that can be analyzed to determine tissue type or condition include complex impedance (real and imaginary components), extracellular impedance, intracellular impedance, interstitial impedance, Examples include, but are not limited to, cell membrane capacitance and intracellular capacitance. In one embodiment, the monitoring device 19 is for measuring impedance profiles or other bioelectric properties known to identify or correlate selected tissue characteristics rather than analyzing the entire frequency spectrum of the profile. May be configured to analyze only selected frequencies. Such frequencies can be selected from pre-existing databases or can be determined in vivo using the swept frequency method described herein. This approach offers the advantage of faster signal processing time and allows faster tissue assessment and diagnosis using less computational resources. This in turn allows the size, output requirements and complexity of the control and display equipment to be reduced.
[0047]
7-10, in related embodiments, apparatus 10 and monitoring device 19 may be configured to utilize complex impedance curves to identify and characterize different tissue types and conditions. Accordingly, the monitoring device 19 may be configured to measure, generate and display a complex impedance curve or profile 19pc. The curve can be both two-dimensional and three-dimensional. For a two-dimensional plot, the x-axis can be a real component and the y-axis can be an imaginary component, while a three-dimensional plot can include an axis for time or frequency. This receives input from the impedance array 22a and performs complex impedance calculations and curve fittings known in the art or the transform function described herein, followed by the impedance displayed on the display device 21. This can be achieved by an algorithm in the module 19m that outputs the profile 19p. As shown in FIGS. 7a and 7b, because tissue conducts differently in frequency, measurements made over a range of excitation frequencies yield an impedance frequency response curve 500 (FIG. 7a) or a series of complex impedance frequency response curves ( FIG. 7b). Using the frequency response curve from either FIG. 7a or 7b, has the highest sensitivity to a given tissue type or condition and / or the highest predictive value for the desired tissue type or condition A particular frequency can be selected for subsequent impedance complex impedance determination and analysis that yields a complex impedance curve with Selection can be made using the methods described herein, or by calibration to a set of in vitro standards representative of the desired tissue condition, by user visual determination / estimation, or a combination of both .
[0048]
As shown in FIGS. 8a-8c, in one embodiment, the process of debonding can be monitored using impedance determinations made at multiple frequencies. The impedance at some frequencies may rise, fall, or both over the time course of delamination. Combining impedance data from multiple curves greatly increases the overall predictive value of a measurement for a stripping event or endpoint. Thus, using a differential diagnostic methodology, the peel monitoring algorithm or module looks for impedance feature curve shapes, slope thresholds, etc. in two or more impedance curves created at different frequencies as an indicator of the peel endpoint. Can be configured for. Such information provides a more reliable indicator of clinical endpoints and can be used to monitor and titrate the release energy or release treatment delivery to demand. Similarly, as shown in FIG. 8d, differences in impedance-frequency spectra before, during and after stripping can also be used to monitor and evaluate the stripping process.
[0049]
In the related embodiments shown in 8e-8g, complex impedance curves can be used to monitor and evaluate the ablation process including the determination of clinical endpoints described herein. As further shown in FIGS. 9a-9c, the device can be configured to utilize complex impedance curves to identify and characterize different tissue types, tumors, and the like. Related embodiments may be configured to generate and display a three-dimensional plot of complex impedance that utilizes time and / or position as the third axis. For a 3-D plot of position, the locus of impedance 502 can be displayed graphically and as shown in FIG. 10, or another graph format known in the art, including 2-D It is. Impedance loci can also be utilized to characterize the ablation process and vector analysis of RF or microwave currents, or other ablation energy vectors (eg, ablation energy magnitude and direction), and cell necrosis (eg, It can be used to perform vector analysis of physiological indicators of changes in interstitial conductivity. In various embodiments, impedance loci can be utilized to facilitate placement and display of tumor volume, exfoliation volume, or other desired tissue mass or volume at the target tissue site. The generation and display of impedance loci 5li (in 2-D or 3-D) gives the physician an easily identifiable visual cue regarding placement, size or detachment movement, tumor or other selected tissue volume. It can be configured to provide.
[0050]
In addition to identifying tissue type, this monitoring device can also be used with an impedance sensing array to monitor the progress of the ablation procedure in real time, including the progress of the ablation volume resulting from the delivery of energy to the target tissue volume. This reduces damage to the tissue surrounding the target mass to be excised. By monitoring impedance at various points inside and outside the tissue site, a determination can be made around the selected tissue mass, as well as when cell necrosis has been completed. If the sensor results at any time determine that the impedance level or ablation endpoint has been met or exceeded, an appropriate feedback signal is input to the power supply, which is then delivered to the electrode. If the ablation energy is stopped or not, the level is adjusted. This target tissue site can also be probed and interrogated by the sensor array after completion of the ablation to confirm that the ablation is complete for the entire ablation volume of the desired volume. By probing the ablation area with this sensor array, the three-dimensional volume of the ablation can be assessed and the margin of the resected healthy tissue beyond the tumor mass can also be measured.
[0051]
Referring now to FIG. 11, which is an embodiment for monitoring the ablation process, this impedance signal strength 510 for a tissue sample volume connected by two members or sensing members or arrays is measured by a monitoring device, a power supply Alternatively, it can be monitored over time using other bioelectric signal monitoring means known in the art. The end point for ablation may be determined based on either a selectable threshold 514 of signal 510 or an inflection point on curve 506 or a change in slope 512 (eg, differentiation) or a combination of both. In one embodiment, the signal 506 is an approximation of the baseline (or reference) impedance determination value 508 of a nearby but not ablated tissue volume from the real-time measurement 504 of the target tissue volume during the time course of ablation. Subtraction can be included. This compensates for any signal or tissue thermal history over time. The threshold 514 and signal 510 may be input and stored in a logic resource embedded in an electronic algorithm that controls energy delivery that may be coupled to an impedance monitoring device or stored in a controller or processor coupled to a power source.
[0052]
Here, with regard to further consideration of the introducer, in various embodiments, the introducer is a trocar, catheter, multi-lumen catheter, or wire reinforced polymer shaft or metal braided polymer shaft, port device, subcutaneous port device, elongate delivery device. Or other medical introduction device known to those skilled in the art. In various embodiments, the introducer as well as the elastic members can have various mechanical properties along their respective lengths (e.g., variable stiffness, torqueability, column strength, bend rate, indentation capability, traceability and Other mechanical performance parameters known in the catheter art, including but not limited to). Referring to FIG. 12a, this can be accomplished by the use of a rigid shaft section 520 disposed in the introducer portion along its length 522. This is also achieved by the use of blades, varying diameters / tapered diameters and different materials (eg, stiffer materials connected to a flexible material) placed over a portion of the introducer. Can be done. Sections 520 made of different materials can be used in introducer connection methods known in the art (eg, with and without capture tube / collate) hot melt connection, adhesive connection, butt connection, etc. ). The connection method can be controlled / selected to control the mechanical transition 12mt between the two sections to the desired slope (eg, smooth vs. stepped). In related embodiments, introducer 12 and / or member 18 are configured to have a stiffer proximal portion and a more flexible distal portion to facilitate one or more of the following. Obtain: (i) placement of the introducer distal tip 16 at the introducer operability and selectable target tissue site, (ii) perforation, detachment and other trauma during placement of the introducer at the tissue site Reduced risk. In various embodiments, the transition from the more rigid part to the more flexible part may be configured to be either: (i) with a linear transition or a curve-linear transition Sequential, (ii) stepped or stepped transitions, and (iii) combinations thereof.
[0053]
Referring to FIGS. 12b and 12c, introducer 12 may have a substantially annular, semi-circular, oval or crescent shaped cross section 12cs along its length, and combinations thereof. Similarly, lumen 13 may have an annular, semi-circular, oval or crescent cross section for all or a portion of the length of introducer 12.
[0054]
Suitable materials for introducer 12 and elastic member 18 include, but are not limited to: stainless steel, shape memory alloys (eg, nickel titanium alloys), polyester, polyethylene, polyurethane, Pebax®, Polyamides, nylons, copolymers thereof and other medical plastics known to those skilled in the art. All or a portion of introducer 12 may be coated with a lubricious coating or film 524 that reduces the friction (and thus trauma) of introducer 12 with liver tissue, lung tissue, bone tissue and other tissues. Such coatings may include, but are not limited to, silicone, PTFE (including Teflon®) and other coatings known in the art. Also, all or a portion of apparatus 10 (including introducer 12 and member 18) is optimized and / or compatible with radiation sterilization (eg, gamma or E-beam) as known in the art. Can be constructed from materials. In a related embodiment, all or a portion of the apparatus 10 is plasma (eg, H ₂ O ₂ )) Can be configured to be sterilized by sterilization (eg, the ratio of lumen diameter to length).
[0055]
Referring now to FIG. 13, in other embodiments, all or a portion of introducer 12 or elastic member 18 may be configured to be bendable and / or steerable using deflection mechanism 25. The deflection mechanism 25 may include a pull wire 15, a ratchet wheel, a cam, a latch and lock mechanism, a piezoelectric material, and other deflection means known in the art. The amount of deflection of the introducer 12 is selectable and can be configured to allow movement of the introducer 12 by oblique rotation in tissues, organs, organ tubes, and blood vessels. In certain embodiments, the distal portion of introducer 12 is configured to deflect more than 0-180 ° in up to three axes to allow the tip of introducer 12 to have a retrograde capability. Can be done. The deflection mechanism 25 may be connected to or integrated with an actuator 24 ″, 25 ′ that may move or slide on the handpiece 24. The mechanism 25 and the connected actuator 25 ′. Is configured to allow the physician to selectively control the amount of deflection 25 of the distal tip 16 or other portion of introducer 12. Actuator 25 'is the rotational and longitudinal direction of the actuator. Can be configured to both rotate and deflect the distal tip 16.
[0056]
Referring now to FIG. 14, in various embodiments, introducer 12 can be coupled to handle 24 or handpiece 24 at its proximal end 14. The handpiece 24 may be removable and may include a port 24 ′ and an actuator 24 ″. The port 24 ′ may be coupled to one or more introducer lumens 13 (and then electrode lumens 72) and Fluid and gas ports / connectors and electrical or optical connectors may be provided, hi various embodiments, the ports include aspiration (including tissue aspiration), and cooling, electrolytic, perfusion polymers and the present specification. Can be configured for delivery of other fluids (both liquid and gas) described in the document: ports are luer fittings, valves (one-way, two-way), robust and boost connectors, swages Fittings and other adapters and medical fittings known in the art may be provided, but are not limited to ports. It can also be equipped with remo-connectors, computer connectors (series, parallel, DIN, etc.) micro-connectors and other electronic variants well known to those skilled in the art, and the port can be an illumination source, eyepiece, video monitor, etc. An optoelectronic coupling may be provided that allows optical and electronic coupling of the optical fiber and / or viewing scope to the actuator 24 ". The actuator 24" may include a rocker switch, pivot bar, button, knob, ratchet, lever, slide and Other mechanical actuators known in the art may be provided. All or some of these may be indexed. These actuators may be configured to be mechanically, electromechanically, or optically coupled to retractor wires, deflection mechanisms, etc. that allow selective control and steering of introducer 12.
[0057]
Handpiece 24 may be connected to tissue aspiration / collection device 26, fluid delivery device 28 (eg, infusion pump), fluid reservoir (cooling, electrolysis, perfusion, etc.) 30 or power supply 20 through the use of port 24 '. . The tissue aspiration / collection device 26 may comprise a syringe, a vacuum source coupled to a filter, or a collection chamber / bag. The fluid delivery device 28 may comprise a medical infusion pump, a Harvard pump, a syringe, and the like. In certain embodiments, the suction device 26 may be configured to perform a chest puncture.
[0058]
Turning now to the discussion of the electrode or elastic member 18 and the sensing member 22m, these members may be of different shapes, sizes and configurations with various mechanical properties selected for a particular tissue type. . In one embodiment, member 18 can be a needle, which is in the size range of 28-12 gauge, and in particular embodiments is 14 gauge, 16 gauge, and 18 gauge. The elastic member 18 is configured to be in a non-deployed position that remains held in the introducer 12. In this undeployed position, the elastic member 18 can be in a miniaturized state, can be spring loaded, and can generally be configured within the introducer 12, or made of a suitable shape memory alloy (eg, nitinol). It may be substantially linear. When the elastic members 18 are advanced out of the introducer 12, they are spring or shape memory that collectively define a delamination volume 5av from which tissue is exfoliated as illustrated more fully in FIGS. As a result, it is expanded to an expanded state. Selectable deployment of the elastic member 18 can be achieved by one or more of the following approaches:
(I) the amount of travel of the elastic member 18 from the introducer 12;
(Ii) independent progression of the elastic member 18 from the introducer 12;
(Iii) the length and / or size of the energy delivery surface of electrodes 18 and 18 ';
(Iv) variations of materials used for electrode 18;
(V) selection of the amount of spring load or shape memory of the electrode 18;
(Vi) variations in the geometric configuration of the electrode 18 in the deployed state; and
(Vii) Preliminarily formed so as to estimate the curvature when the elastic member 18 is advanced from the introducer 12.
[0059]
As described herein, in various embodiments, all or a portion of the elastic member 18 can be an energy delivery device or member 18e. Turning to the discussion of energy delivery devices and power sources, specific energy delivery devices 18e and power sources 20 that may be used in one or more embodiments of the present invention include, but are not limited to:
(I) a microwave power source coupled to a microwave antenna that provides microwave energy in a frequency range of about 915 MHz to about 2.45 GHz;
(Ii) an RF power source coupled to a radio frequency (RF) electrode;
(Iii) a coherent light source coupled to an optical fiber or light pipe;
(Iv) a non-coherent light source coupled to an optical fiber;
(V) a heated fluid coupled to a catheter having a closed lumen or at least partially open lumen configured to receive the heated fluid;
(Vi) a cooling fluid coupled to a catheter having a closed lumen or at least partially open lumen configured to receive the cooling fluid;
(Vii) a cryogenic fluid;
(Viii) a resistance heating source coupled to the conductive wire;
(Ix) an ultrasonic power source coupled to an ultrasonic emitter, wherein the ultrasonic power source generates ultrasonic energy in the range of about 300 KHz to about 3 GHz, (xi) and combinations thereof. To facilitate discussion of the rest of this application, energy delivery device 18e is one or more RF electrodes 18, and the power source utilized is an RF power source. For these and related embodiments, the RF power source 20 delivers 5 to 200 watts, preferably 5 to 100 watts, and even more preferably 5 to 50 watts of electromagnetic energy to the electrodes of the energy delivery device 18e without interference. Can be configured to. These electrodes 18 are electromagnetically coupled to the energy source 20. This coupling can be direct from the energy source 20 to each electrode 18 or can be indirect by using a collet, sleeve, etc. that couples one or more electrodes to the energy source 20.
[0060]
In various embodiments, the electrode 18 comprises at least one sensor 22 and the detection member 22m can have a variety of shapes and geometries. Referring now to FIGS. 15a-15f, exemplary shapes and geometries include, but are not limited to, ring-like, ball, hemispherical, cylindrical, conical, needle-like and combinations thereof. . Referring to FIG. 16, in one embodiment, electrode 18 may be a needle with sufficient sharpness to penetrate tissue, including fibrous tissue, including encapsulated tumor cartilage and bone. The distal end of electrode 18 may have a cut angle in the range of 1 ° to 60 °, with a range of at least 25 ° or at least 30 ° being preferred, and in particular embodiments 25 ° and 30 °. The surface of the electrode is smooth or embossed and can be concave or convex. The electrodes 18 may have different lengths 38 that are advanced from the distal end 16 ′ of the introducer 12. These lengths may be determined by the actual physical length of the electrode 18e, the length 38 'of the energy delivery surface 18eds of the electrode 18 and the length 38 "of the electrode 18 covered by the insulator 36. Examples of the length 38 include, but are not limited to, a range of 1-30 cm, and in particular embodiments, 0.5 cm, 1 cm, 3 cm, 5 cm, 10 cm, 15 cm, and 25.0 cm. The conductive surface area of 0.05mm ² ~ 100cm ² Range. The actual length of electrode 18 depends on the location of the tissue site to be ablated, the distance from that site, its accessibility, and whether the physician performs an endoscopic or surgical procedure. On the other hand, the conductive surface area 18eds depends on the desired peel volume to be produced.
[0061]
Referring now to FIGS. 17 and 18, the electrode 18 may also be configured to be flexible or deflectable with one or more radii of curvature 70 that may exceed 180 degrees of curvature. In use, the electrode 18 can be positioned to heat, necrotize, or exfoliate any selected target tissue volume. The radiopaque marker 11 can be coated on the electrode 18e for visualization purposes. Electrode 18 may be introduced into introducer 12 and / or progression member or device 15 or progression using joining methods known in the field of soldering, brazing, welding, pressure bonding, adhesive bonding and other medical devices. -It can be connected to the retracting member. The electrode 18 may also include one or more coupled sensors 22 to measure temperature and impedance (both electrode and surrounding tissue), voltage and current, electrodes and other physical properties of adjacent tissue. . The sensor 22 can be on the outer surface of the electrode 18 at its distal end or middle section.
[0062]
The electrode 18 can be made of a variety of conductive materials, metallic and non-metallic. Suitable materials for electrode 18 include steel (eg, subcutaneous injection quality 304 stainless steel), platinum, gold, silver and alloys, and combinations thereof. The electrode 18 can also be made of a conductive solid or hollow straight wire of various shapes (eg, round, flat, triangular, square, pentagonal, elliptical, etc.). In certain embodiments, all or a portion of the electrode 18 or the second electrode can be made from a shape memory alloy (eg, NiTi commercially available from Raychem Corporation, Menlo Park, California).
[0063]
Referring now to FIGS. 19-22, in various embodiments, the one or more elastic members or electrodes 18 have non-external surfaces that are fully or partially insulated and are energy delivery surfaces. It can be covered by an insulating layer 36 to provide an insulating region. In the embodiment shown in FIG. 19, the insulating layer 36 can be fixed or slidably positioned along the length of the electrode 18 to vary and control the length of the energy delivery surface. A sleeve may be provided. Suitable materials for the insulating layer 36 include polyamides and fluorocarbon polymers (eg, TEFLON®).
[0064]
In the embodiment shown in FIG. 20, the insulator 36 is formed outside the electrode 18 in a peripheral pattern, leaving a plurality of energy delivery surfaces. In the embodiment shown in FIGS. 21 and 22, the insulator 36 extends along the longitudinal outer surface of the electrode 18. Insulator 36 may extend along a selected distance along the longitudinal length of the electrode and around a selectable portion of the outer periphery of the electrode. In various embodiments, the electrode section can have an insulator 36 along a selected longitudinal length of the electrode and completely surrounding one or more peripheral sections of the electrode. The insulator 36 positioned outside the electrode 18 can be varied to define any desired shape, size and geometry of the energy delivery device.
[0065]
Referring now to FIGS. 23a and 23b, in various embodiments, the electrode 18 includes one or more lumens 72 (which may be connected to a plurality of fluid distribution ports 23, which may be openings). May be continuous with the lumen 13 or may be the same) from this port through which various fluids 27 (conductivity enhancing fluid, electrolytic solution, saline solution, cooling fluid, cryogenic fluid, Gas, chemotherapeutic agents, pharmaceuticals, gene therapy agents, phototherapeutic agents, contrast agents, injection media and combinations thereof) can be introduced. It has a port or opening 23 fluidly connected to one or more lumens 72 that are connected to lumen 13 (which in turn is connected to fluid reservoir 30 and / or fluid delivery device 28). Is achieved.
[0066]
In the embodiment shown in FIG. 23a, the conductivity enhancing solution 27 can be injected into the target tissue site 5 ′ containing the tissue mass. This conductivity enhancing solution may be injected before, during or after delivery of energy to the tissue site by the energy delivery device. The injection of the conductivity enhancing solution 27 into the target tissue 5 ′ has been increased or otherwise controlled to act as an enhanced electrode 40 (as compared to non-implanted tissue). Alternatively, an implanted tissue region is generated having a region of controlled tissue impedance 40. During RF energy delivery, the tissue impedance and the current density at the enhanced electrode 40 is greater in the electrode 40 and the target tissue 5 'without the RF power supply being turned off due to excessive localized impedance. Controlled to an optimal level that allows RF power to be delivered. In use, injection of a target tissue site with a conductivity enhancing solution provides two important benefits: (i) faster ablation time; (ii) creation of larger damage; and (iii) ) Reduction of the incidence of impedance related outages of RF power. This is due to the fact that this conductivity enhancing solution prevents desiccation of tissue adjacent to the electrode, which reduces current density and otherwise results in increased tissue impedance. These and related embodiments also significantly increase the risk of pad burns to the patient due to the use of lower power levels that reduce current density at the interface between the patient's skin and the ground pad electrode. To provide reduced benefits.
[0067]
A preferred example of the conductivity enhancing solution is a hypertonic saline solution. Other examples include fluoride salt solutions, colloidal magnetic solutions, and colloidal silver solutions. The conductivity of the enhanced electrode 40 is increased by controlling the rate and amount of injection and having a higher concentration of electrolyte, and thus using a solution with higher conductivity (eg, saline). obtain. In various embodiments, the use of the conductivity enhancing solution 27 allows delivery of power up to 2000 watts to the impedance stop tissue site, and in certain embodiments, 50 watts, 100 watts, 150 watts, 250 watts. 500 Watts, 1000 Watts and 1500 Watts are achieved by varying the flow, amount and concentration of the infusion solution 27. The injection of the solution 27 can be continuous, pulsed, or a combination thereof and can be controlled by the feedback control system 329 described herein. In certain embodiments, a bolus of infusion solution 27 is delivered prior to energy delivery, after which continuous delivery is initiated prior to or during energy delivery using energy delivery device 18e or other means.
[0068]
In various embodiments, the device may be equipped with impedance measurement methods, tissue excision capabilities, and may be configured to control tissue impedance at a target tissue site as well as inject fluid. An embodiment of an ablation device configured for tissue injection tissue for impedance control is shown in FIG. 23b. In this and related embodiments, the liquid delivery device 28 can be a syringe pump configured with a plurality of syringes 28s, a plurality of bore syringes 28b, each syringe in a separate liquid lumen or channel 72, They are connected directly or via a valve (eg, an indexing valve). Related embodiments of the infusion device 28 include multi-lumen tubing or multiple tubes connected to one or more electrode lumens 72 via an index valve and other channels within the exterior of the introducer lumen 13 or introducer 12. Channel tubing may be provided. Multi-channel tubing can be made from PEBAX, silicone, polyurethane, or other resilient polymers using extrusion techniques known in the art. The use of an index valve allows independent control of the flow rate through the individual lumens 72 and thereby allows independent control of the injection through the electrode 18. This in turn allows for further control of the implantation process, including the production of smaller area implants or larger area implants around the individual electrodes 18. Such control is particularly beneficial for bipolar embodiments. In this embodiment, it is desirable not to have a continuous implantation region between one or more bipolar electrodes 18 and the return electrode to prevent shortening.
[0069]
As described herein, the tissue ablation device may be configured to inject fluid 27 to control or maintain tissue impedance at a target tissue site. In various embodiments, this is controlled for feedback control devices, systems, fluid delivery devices, and algorithms described herein and known in the art (eg, proportional control, proportional integral control, or proportional integral). Can be achieved using a differential method. Further, as shown in FIG. 23c, the feedback control system receives an input signal or monitoring signal from the monitoring device and outputs a control signal to the device to provide a fluid delivery device (or fluid delivery control, not shown). And can be coupled to an impedance monitoring device. Delivery of fluid to the tissue site can be a controlled flow or pressure. Thus, in various embodiments, the control system adjusts the impedance by adjusting the infusion flow rate through one or more channels, the pressure of the infusion fluid in the channels, or a combination of both. The flow rate can be controlled in the range of about 0.01 to about 2.5 ml / channel (in certain embodiments, 0.1, 0.25, 0.5, 0.75, 1.0, 1.5 , And 2.0 ml / min). The pressure can be controlled in the range of 0.01-5 atm (in certain embodiments, at 0.1, 0.25, 0.5, 0.75, 1.0, 1.5, and 2.5 atm. is there).
[0070]
Fluid delivery method with related features as described in US patent application Ser. No. 60 / 290,060 (filed May 10, 2001, which is fully incorporated herein by reference). And other embodiments of the ablation device may be used.
[0071]
We now discuss an impedance type 22 that can be measured and controlled in various embodiments of the present invention. These include system impedance and local impedance. Local impedance is impedance 22 along a conductive path in the target tissue site that can be measured between one or more electrodes in bipolar embodiments. This system impedance is the local impedance along the conductive path, the impedance in the conductive path between the rest of the body (abdomen, leg, skin, etc.) and the ground pad electrode, the impedance of the ground pad electrode, the RF generator Impedance, trocar or delivery device impedance, electrode impedance, and all associated cables that connect one or more elements of this apparatus to the devices and elements described herein (eg, RF generators, etc.) Is the cumulative impedance of Local impedance can be measured directly by measuring the impedance along the conductive path between one or more electrodes in a bipolar embodiment. Alternatively, the local impedance can be measured indirectly by taking a reference impedance measurement of the system impedance prior to the ablation treatment and then subtracting this value from the impedance measurement during the ablation treatment. In related embodiments, the impedance of the apparatus and RF generator may be pre-determined using a calibration device or a pre-calibrated tissue / body impedance simulator. Again, these values can be stored and subtracted from the real-time system impedance measurements to obtain local impedance.
[0072]
The local impedance can be determined between one or more electrodes, or by coating the outer part of the electrode with an insulating coating so that current flows between the non-insulated outer part and the inner part of the electrode It can be determined between the inside and the outside of the hollow electrode. Alternatively, all or part of the electrodes can comprise a coaxial cable comprising an inner electrode and an outer electrode.
[0073]
Here, the impedance determination and calibration used by the various embodiments of the present invention will be discussed. In one embodiment, the impedance measured by the impedance measurement device or power generator is the system impedance. System impedance includes local impedance (LI) from the target tissue site and local impedance (BI) from the rest of the body and local impedance from ground pads and generators and cables. Typically, the impedance (BI) from the rest of the body is constant and the local impedance (LI) varies. This allows indirect determination of local tissue impedance by taking a reference impedance measurement (either before RF power delivery or at the start of delivery) and then subtracting the reference measurement. The determination of local tissue impedance and system impedance allows measurement of a parameter known as impedance efficiency (IE). This value is the ratio of local tissue impedance to system impedance (LI / SI). The IE value allows measurement of another parameter known as power loss efficiency (PDE). This value is the ratio of the amount of RF power that is actually lost at the target tissue site (due to ohmic heat) to the total power delivered from the RF generator for a given power setting. The PDE can theoretically be determined by applying IE to the RF power setting. By maximizing PDE, the amount of power dissipated in the lesion is maximized, so the lesion is heated and heat induces necrosis. In general, a higher PED will result in faster, larger and more optimal ablation while minimizing the risk of pad burn by reducing the power required to obtain the ablation volume. Enabling and thus creating a current density at the contact surface between the patient's skin and the ground pad or return electrode connected to the RF generator.
[0074]
The PDE can be optimized / maximized by various means comprising the control systems and methods described herein. Accordingly, various embodiments of the present invention may be configured to optimize PDE by control of one or more parameters including but not limited to: target tissue site impedance (as a function of distance from electrode) Target tissue impedance gradient), electrode impedance, electrode surface impedance, system impedance, and target tissue current density (including current density gradient as a function of distance from the electrode). One or more of these parameters may be a set point that is controlled using the control systems and methods described herein. In the embodiment shown in FIG. 23d, the PDE is maximized by controlling the system impedance and / or local impedance to or near the optimum value 526. Prior art RF ablation approaches were believed to maximize the delivery of power to the tissue site by minimizing system impedance. Embodiments of the present invention use a contrasting and novel approach by controlling the impedance (either local or system) above the minimum and to an optimum value to maximize the PED. This optimal value is higher than the minimum value if the local impedance is too low for the target tissue site relative to the rest of the body (eg, the legs, torso, and the contact surface between the ground pad and the skin) This is because the power that is lost at the time decreases. This approach used by the various embodiments of the present invention departs fundamentally from previous RF ablation methodologies based on the idea that lower tissue impedance is better. Embodiments of the present invention are configured to achieve increased power delivery to the tissue site by actually increasing the local impedance to a higher level to obtain an increased IE value.
[0075]
As shown in FIG. 23d, tissue impedance below optimal impedance 526 results in a sharp drop in power 528 delivered to curve 530 (eg, second order, curvlinear decrease or logarithmic decrease). On the other hand, values above the optimum impedance result in a more gradual linear or asymptotic decrease. Using this and associated curves, the power delivered to the target tissue site is controlled by controlling the local impedance via the injection rate of the conductive solution or other means described herein. obtain. Thus, in various embodiments, the local impedance is above or below the optimal impedance over the time course of the ablation treatment, not only to match the optimal impedance value or optimal impedance range 532. It can be controlled to be maintained at the value. In use, this allows the physician to more accurately titrate the exfoliation energy for a particular tumor volume size, shape and density, and kills the local anatomy (eg, near or inside the blood vessel) It becomes possible to make it. In addition, these and related embodiments allow physicians to quickly increase or decrease the delivered power over the time course of the ablation without having to change the power setting to the RF generator. Become. Various embodiments of the present invention provide a pre-programmed flow profile or program (stored in the storage device described herein) to generate a time-variable local impedance profile over the time course of stripping. May be included. For example, the flow rate can be programmed to operate to the right side of the linear portion of curve 530 to gradually increase the delivered power, then shift to the impedance value of the optimal impedance and then strip Immediately before the end of, the impedance is shifted to the left of the optimum impedance in order to quickly reduce the delivered power. This embodiment provides the benefit of minimizing damage to the surrounding healthy tissue just before the end of detachment. Alternatively, the reverse profile can be used. Related embodiments may include an injection / impedance profile with multiple intervals that shift to the left and right sides of the optimal impedance. This device also allows the physician to manually control the flow / impedance profile to suit individual tumor volume needs. The injection profile / impedance profile database may be stored in a storage device or database.
[0076]
As described herein, in various embodiments, the optimum impedance can be controlled and maintained by injecting a conductive solution into the target tissue site to control the local impedance. This may be accomplished by input measurements from sensors and / or electrodes to a control system that is electrically connected to the infusion device described herein. In various embodiments, the control system can be a closed loop system using proportional methods, PI methods, PID methods and fuzzy logic algorithms known in the art. The control system can be configured to control both the flow rate and conductivity of the injected solution by controlling the electrolyte concentration / salt concentration of the injected solution. Referring back to FIG. 23a, the control of the conductivity of the injected solution can be achieved by connecting a source of dilute solution and a reservoir via a control valve, or by including a concentrated electrolyte solution and a dilute electrolyte solution. This can be accomplished by configuring the reservoir to have more than one chamber. In any embodiment, the control valve uses a conductive center / pH sensor known in the art to monitor the output electrolyte concentration and at a rate to achieve the desired electrolyte concentration. Can be used to mix.
[0077]
In related embodiments, two or more process parameters can be controlled to maintain local or system impedance with optimal impedance values. In one embodiment, the RF generator power and injection rate can be controlled in a coordinated manner to control local impedance or system impedance. In situations where the impedance is too low, the RF power can be increased and the injection rate can be decreased. This helps to dry the target tissue site by vaporizing the fluid from the target tissue site or by otherwise flushing and / or allowing the fluid to dissipate from the tissue site. . Alternatively, the fluid delivery system may be connected to a vacuum device or other configured to apply negative pressure to draw fluid from the target tissue into the electrode lumen or introducer lumen. If the impedance is too high, the injection rate can be increased with decreasing RF power level.
[0078]
In various embodiments, the optimal impedance or impedance range can be maintained in the range of 5-200Ω, and preferably can be maintained in the range of 30-150Ω, and in certain embodiments 10Ω, 15Ω, 20Ω, 30Ω, It can be 40Ω, 50Ω, 75Ω, 80Ω, 90Ω, 100Ω, 110Ω and 120Ω. The optimal impedance value is a calibration calibrator that can be configured to simulate local tissue impedance and / or body impedance using calibration software programs and / or biomedical device calibration methods known in the art. (Not shown) can be used. In use, the physician connects the ablation device or catheter and an RF generator to determine the optimum impedance characteristic value for a given catheter and generator combination. Alternatively, each catheter can be manufactured and calibrated using biomedical device calibration methods known in the art. This value is stored in a microprocessor or ROM chip known in the art, which are integrated or connected to the apparatus and configured to communicate the measuring device and / or generator. Also, the control system, measurement device, or generator can be configured to allow the physician to manually enter a value for optimal impedance.
[0079]
In the embodiment shown in FIG. 23e, solution injection can be controlled to control the position impedance profile or gradient 534 (which varies as a function of distance from the electrode) and hence the power dissipation gradient 536 can be controlled. An optimal impedance gradient 538 is selected, and then an optimal power dissipation gradient 540 can be generated to optimize the delivery of power to the target tissue site. In one embodiment, the injection rate can be controlled to maintain the impedance gradient substantially constant (in shape and position) over the time course of stripping. Alternatively, the flow rate is increased or decreased as needed by the control system 329 to shift the impedance gradient over the time course of the stripping RF power delivery in order to optimize the stripping volume and to minimize the stripping time. obtain. Lower injection rate (and / or lower electrolyte concentration) shifts the impedance gradient to the right side, delivering more power to the target tissue to produce a larger exfoliated volume in a short time Enable. Increased infusion rate allows the impedance gradient to be shifted to the left, minimizes tissue desiccation and tissue charring, and avoids impedance-induced generator shutdown (so-called impeding out) Or reduce. In alternative embodiments, the fluid injection may be configured to generate a steady impedance profile 546, 548 or an increasing slope 542, 544. The use of optimal impedance gradients provides the benefit of more accurate or more precisely controlled control of the ablation process by counteracting impedance differences within the target tissue site, particularly the site adjacent to the electrode. In various embodiments, the impedance gradient 534 can be configured to be a linear function, logarithmic function, quadratic function, cubic function, or other polynomial function. Flow programs or flow subroutines that can be used to generate such gradients can be stored in storage and / or logic devices.
[0080]
Here, instead of discussing the sensor, in various embodiments, the sensor may comprise all or some of the elastic members. Referring back to FIG. 19, when the elastic member 18 is made from a conductive material, the length of the sensor 221 can be defined by the arrangement of a slidable or fixed thermal insulation layer 36. Also, in various embodiments, sensor 22l can be made from a variety of conductive materials and metals known in the art, including stainless steel, copper, silver, gold, platinum and alloys and combinations thereof. . Referring now to FIG. 24, similarly, all or a portion of sensor 22, or sensor member 22m, may be provided with a conductive metal layer or conductive polymer coating 22c (which is known in the art). A method (eg, sputtering, vacuum deposition, immersion coating, photolithography, etc.) is used to coat or deposit a selected portion of the thermal insulation member 18). In related embodiments, sensor member 22m and / or sensor 22 may be configured to have a resistance gradient 22g along their entire length or a portion of their length. The resistance gradient can be increased or decreased in a linear manner, a second order manner, a third order manner, an exponential manner or other manner. In certain embodiments, the resistance gradient is configured to correct for resistance loss (ie, voltage resistance loss) and / or history that occurs along the length of the sensor 22, and the temperature of the sensor 22 and / or Changes in the overall resistance of the sensor 22 due to changes in the conductive length / sensor length 22lc (and region) can be caused by the forward or backward movement of the slidable thermal insulation layer, or by a sensor with charred burnt tissue or other adhesive tissue. It can occur due to deterioration. In this embodiment and related embodiments, the gradient can be configured to produce a minimum resistance (eg, maximum conductance) at the distal tip 22d of the sensor 22 and moves gradually in the proximal direction. The gradient is generated through the use of coating 22c by changing either the coating thickness or composition, or a combination of both along the sensor length 22l, using methods known in the art. Can be done. Furthermore, by correcting for such resistance changes or loss along the sensor length or region, these embodiments and related embodiments also provide detection of the real and imaginary components of the complex impedance. Improve. In other related embodiments, the resistance gradient may be radial with respect to sensor length 22l or may be a combination of radial and linear directions.
[0081]
In other embodiments, the sensor may comprise a number of biomedical sensors known in the art including, but not limited to, thermal sensors, acoustic sensors, optical sensors, voltage sensors, current sensors, pH Sensors, gas sensors, flow sensors, position sensors, pressure sensors / stress sensors. The thermal sensor can comprise a thermistor, thermocouple, resistance wire, optical sensor, and the like. The acoustic sensor can comprise an ultrasonic sensor comprising a piezoelectric sensor that can be configured in an array. The pressure sensor and the stress sensor may comprise a strain gauge sensor comprising a silicon based strain gauge.
[0082]
In one embodiment, the sensor may be selected to measure temperature along with impedance to correct for any temperature related excursions or history in impedance determination. Thus, in one embodiment, feedback signals from a temperature sensor or temperature calculation device can be input to the impedance calculation device described herein to correct for these changes. Temperature monitoring can also be used for real-time monitoring of energy delivery. If any time deadline from the sensor determines that the desired cell death temperature is excessive, an appropriate signal is sent to the controller and then adjusts the amount of electromagnetic energy delivered to the electrode.
[0083]
Referring now to FIGS. 25a-25c and 26a-26c, in one embodiment, the location and size of the exfoliation volume generated by the delivery of electromagnetic energy can be controlled via the frequency of exfoliation energy delivered. At lower electromagnetic frequencies (e.g., radio frequencies (e.g., 1 kHz to 1 MHz), more localized energy concentrations (e.g., current density) are generated and the resulting energy concentration region or delamination region 5az has a lateral distance of 18 dl or others Occurs near the energy delivery electrode / antenna, with higher frequencies (eg, microwaves) resulting in farther energy concentrations and resulting far more stripped regions, as shown in FIGS. The location, shape and magnitude of the damage caused by changing the frequency of the delivered energy and / or utilizing energy delivery electrodes / antennas coupled to different frequency energy sources (eg microwave vs. radio frequency) Can be precisely controlled and even guided. Can be achieved by electrically separating one or more electrodes 18 to allow the use of a separate frequency for each electrode. And / or coupled to a control resource coupled to a power source and individual electrodes / antennas such circuitry and control resources to turn on / off individual electrodes or antennas and In use, these and related embodiments can be used to accurately control the size, location, and shape of the lesion and / or treat target tissue. It offers the advantage of allowing it to be titrated to meet demand.
[0084]
Referring now to FIGS. 25b and 25c, in various embodiments, one or more electrodes can radiate or dissipate different wavelengths of energy from different segmented portions 18sp of electrode 18 To have a segmented portion 18sp. Segmentation can be achieved through the use of an electrically insulating section 36s.
[0085]
In the embodiment shown in FIG. 25b, the use of segmented electrodes allows the generation of a segmented release region 5azs that includes a first segmented region 5azs1 and a second segmented region 5azs2. The size and shape of the segmented release region can be controlled by discontinuities or overlaps. Such embodiments also provide the ability to avoid damage to anatomical structures (eg, blood vessels, nerves, etc.). This anatomical structure may be proximal to the tumor to be treated or may be effectively surrounded by the tumor to be treated. For example, in the embodiment shown in FIG. 25b, segmented debond regions 5azs1 and 5azs2 are sufficient to avoid damaging the blood vessel 5bv or other critical structure 5as that exists between two or more electrodes 18. Can be sized and positioned (through frequency control of the stripping frequency delivered to each electrode) to have a space between each region. Alternatively, if desired, the stripping frequency delivered to the segmented portion 18sp of each electrode can be reconfigured to produce overlapping segmented stripping regions 5azs, as shown in FIG. 25c.
[0086]
In use, the medical practitioner positions the device and then images the target tissue site (using an imaging system known in the art, such as medical ultrasound scanning technology or CAT scanning technology). Desired to identify both the tumor and critical structures, and then use that image to control the input frequency to the energy delivery device to completely detach the tumor while avoiding critical structures Generate damage magnitude and shape. In one embodiment, the image can be stored electronically and the tumor and surrounding anatomy can be imaged (such as an edge detection algorithm resident in the imaging device processor). Is analyzed to identify with the output supplied in the power control software module coupled to the power supply (which controls the power frequency to produce the desired peel volume). Another advantage of these embodiments and related embodiments is the ability to generate an energy gradient or thermal gradient within the target tissue site. That is, to measure the energy delivery to address the physical and thermal conditions of a particular tumor mass (even a sub-section of that tumor mass), some amount to a separate section of the target tissue volume The ability to deliver energy. This is an important capability. This is because tumors are often morphologically heterogeneous and therefore thermally heterogeneous (this is a problem that current exfoliation therapies are neither recognized nor addressed).
[0087]
An exemplary embodiment for the use of this capability includes a higher amount of energy in the tumor center to produce higher temperatures to ensure complete detachment at the center and to minimize the risk of thermal damage to surrounding healthy tissue. And a smaller amount of energy to the periphery. Alternatively, the increased energy is also selectively directed to the tissue area created by the RF needle or probe (or other penetrating energy delivery device) as it penetrates into the tumor and surrounding tissue so that the viable malignant tissue becomes RF needle. It can be ensured that it is not pulled back through the area upon removal.
[0088]
Referring now to FIGS. 3 and 27, various embodiments of the present invention include one or more impedance determinants (including, but not limited to, complex impedance, impedance vector, impedance position, and combinations thereof). The image or map is created and displayed. In one embodiment, the process 100 for creating and displaying an impedance map or impedance induced image 4 ′ includes one or more of the following steps, all or a portion of which are described herein. It can be implemented as an electronic instruction set on a processor or logical resource. Impedance array 22a and / or device 10 may be positioned (101) within or near the desired sample volume 5sv and / or conductive path 22cp defines and therefore selects (110) a particular sample volume 5sv. Can be selected (105). The volume is then imaged using all or part of the sensing member 22m or sensor 22 that includes the array 22a (200). Thereafter, a determination (300) may be made to perform one or more re-images of the sample volume to increase image resolution. In addition, different excitation currents can be applied to the target tissue, and voltage measurements can be repeated over time to measure via increased sampling and signal bias or noise reduction that can occur at a particular excitation current. The accuracy and accuracy of the can be increased. Thereafter, signal 22i from impedance array 22a may be signaled or input (400) to logic resource 191r. This logical resource includes a module 19m that may include an image processing sub-module 19mi. Sub-module 19mi includes, but is not limited to, image processing / signal processing methods (edge detection, filtering, approximation techniques, volume imaging, contrast enhancement, fuzzy logic, and other methods known in the art. ) Using a subroutine or algorithm configured to create an impedance map or impedance induced image 4 ′ of all or part of the target tissue volume 5 ′. Alternatively, one or more signals 22i from array 22a may be input or signaled (500) to storage resource 19mr (or an externally linked data storage device) and stored as impedance data set 22ds in storage resource 19mr. obtain. Thereafter, all or a portion of the data set 22ds may be input and processed (600) into the sub-module 19mi as described herein to generate an impedance map or impedance derived image 4 '; This impedance map or impedance induced image 4 ′ may then be displayed (700) on the display device 21 or other display means. Thereafter, a decision 800 can be made to image a new sample volume, and the process starting at the positioning step 101 or the selective conductive path step 105 can be repeated. In one embodiment, the imaging or mapping process is either by rotating the array 22a around the introducer axis 12al, by advancing or retracting one or more sensing members 22m from the member 18, or both This can be facilitated by a combination of
[0089]
In one embodiment, module 19m or 19mi calculates impedance ratio or resistivity from a known voltage and a current measured at one or more conductive paths 22cp in the target tissue volume. It may include an algorithm that utilizes a Laplace equation. A reference measurement or normalization method can be used to account for noise in that measurement. In related embodiments, impedance measurements and other bioelectric measurements described herein can be analyzed and transformed functions (Fourier transforms, fast Fourier transforms, wavelet analysis methods, and known in the art) Other numerical methods may be used to convert from the frequency domain to time. These functions and methods may be incorporated into algorithms or subroutines within module 19m or 19mi. Algorithms that incorporate wavelet functions and transforms (including packets) may be configured to analyze and analyze multidimensional and multifrequency data and related functions and equations. This approach offers the advantage of greater flexibility in applying wavelets to analyze impedance data, conductivity data and other bioelectric data collected using the systems and devices of the present invention. One or more of the following wavelet functions may be incorporated into an algorithm or subroutine in module 19 or 19mi: spline wavelet, waveform modeling and waveform segmentation, time-frequency analysis, time-frequency localization, fast algorithm and filter Bank, integral wavelet transform, multi-resolution analysis, cardinal spline, orthonormal wavelet, orthogonal wavelet space, haar wavelet, shannon wavelet, and meyer wavelet, battle-lumerie ( lemarie spline wavelet and stroeberg spline wavelet; (Daubechies) wavelet; two orthogonal wavelet, orthogonal decomposition and reconstruction; and multidimensional wavelet transform. In an exemplary embodiment, module 19m or 19mi utilizes a spline wavelet to allow analysis and synthesis of discrete data for a uniform tissue sample site or a non-uniform tissue sample site without any boundary effects.
[0090]
The image module 19mi is also a subroutine for performing interpolation (eg, primary spline interpolation, quadratic spline interpolation, or cubic spline interpolation) between determined individual impedance values from an image data set of a predetermined sample volume. Can be included. This improves image quality, including resolution, without any substantial loss of spatial detail or any substantial loss of contrast detail. In a related embodiment, the image processing module 19mi allows the user to select both an interpolation algorithm or other image processing algorithm to be performed, as well as an image region to be processed as such. Can be configured. Thus, the user can choose to augment all or part of the image to provide faster image processing time (by not having to process the entire image) and also the imaging device May improve the image quality of the system and other overall usefulness. The image processing module 19mi may also include gray scale and color contrast capabilities that may be selectable. Both grayscale and color can be adjusted or baseline measurements obtained from individual patients, calibration measurements, or statistical (eg, average) values for patient sample groups, or parameters for patient populations ( For example, average), or a combination thereof.
[0091]
In a related embodiment, the monitoring device 19 and module 19mi may be configured to create an impedance image that maximizes visual discrimination or contrast between tumorous tissue and healthy tissue. This can be accomplished by using a frequency or combination of frequencies that provides the greatest sensitivity for the tissue type that is indicative of the selected tissue type or tumor (eg, vessel distribution temperature, etc.). In one embodiment, such frequency produced the best contrast between performing a swept frequency measurement and between healthy tissue and tumorous tissue or other tissue conditions (eg, thermal damage, necrosis, etc.) One or more frequencies can be used to determine by creating an impedance map or image.
[0092]
Referring now to FIGS. 28 and 29, feedback control system 329 may be coupled to energy source 320, sensor 324, impedance array 322a, and energy delivery devices 314 and 316. Feedback control system 329 receives temperature or impedance data from sensor 324, and the amount of electromagnetic energy received by energy delivery devices 314 and 316 determines the strip energy output, strip time, temperature, and current density (“four Parameter ") is changed from the initial setting. The feedback control system 329 can automatically change any of these four parameters. The feedback control system 329 can detect impedance or temperature, and can change any of the above four parameters depending on any or combination. The feedback control system 329 is a multiplexer (digital) for multiplexing and transmitting temperature sensing circuitry that provides control signals indicative of temperatures or impedances detected by different electrodes, sensors, sensor arrays, and one or more sensors 324. Or analog). A microprocessor can be coupled to the temperature control circuit.
[0093]
The following discussion relates specifically to the use of RF energy as a stripping energy source for the device. For this discussion, energy delivery devices 314 and 316 are now referred to as RF electrodes / antennas 314 and 316, and energy source 320 is now an RF energy source. However, all other energy delivery devices and energy sources discussed herein are equally applicable, and devices and energy sources similar to devices associated with treatment devices include laser optical fibers, microwave devices, etc. Can be used with. The temperature of the tissue or the temperature of the RF electrodes 314 and 316 is monitored and the output of the energy source 320 is adjusted accordingly. The physician may disable the closed loop system or the open loop system if desired.
[0094]
A user of the device can input an impedance value corresponding to a set position placed on the device. Based on this value, along with the determined impedance value, feedback control system 329 determines the optimal power and time required in delivering RF energy. The temperature can also be detected for monitoring and feedback purposes. The temperature is automatically maintained at a certain level by having a feedback control system 329 that regulates the output, and that level can be maintained.
[0095]
In another embodiment, the feedback control system 329 determines the optimal power and time for the baseline setting. The exfoliation volume or damage is initially formed at the baseline. Greater damage can be obtained by extending the peel time after the central core is formed at the baseline. Completion of the lesion creation advances the energy delivery device 316 from the distal end of the introducer to a position corresponding to the desired lesion size, and the periphery of the lesion is achieved so that sufficient temperature is achieved to create the lesion. Can be checked by monitoring the temperature.
[0096]
The closed loop system 329 may also utilize a controller 338 to monitor temperature, adjust RF power, analyze results, retransmit results, and then adjust power. More particularly, the controller 338 governs power levels, cycles, and durations so that RF energy is distributed to the electrodes 314 and 316 to achieve the desired treatment objective and clinical endpoint. Achieving and maintaining appropriate power levels. The controller 338 may also analyze the spectral profile 19p in tandem and perform tissue biopsy identification and detachment monitoring functions (including endpoint determination). In addition, the controller 338 may dominate electrolyte delivery, cooling fluid delivery, and removal of aspirated tissue in tandem. Controller 338 may be integrated with power supply 320 or otherwise coupled to power supply 320. In this and related embodiments, the controller 338 can be coupled to another impedance determining current source 317 and configured to tune delivery of the pulsed output to the tissue site to provide a sensor 324. Alternatively, detection by the sensor or sensor array 322a is allowed during the power off period to prevent or minimize signal interference, artifacts or undesirable tissue effects during sampling by the sensor array 322a. The controller 338 can also be coupled to input / output (I / O) devices such as a keyboard, touchpad, PDA, microphone (coupled to voice recognition software residing on the controller 338 or other computer), and the like. In one embodiment, the current source 317 can be a multi-frequency generator (eg, manufactured by Hewlett Packard Corporation (Palo Alto, Calif.)) And includes a spectrum analyzer manufactured by the same company. Or can be coupled to a spectrum analyzer.
[0097]
Referring now to FIG. 28, all or part of the feedback control system 329 is illustrated. The current delivered through the RF electrodes 314 and 316 (also referred to as first and second RF electrodes / antennas 314 and 316) was measured by a current sensor 330. The voltage was measured by voltage sensor 332. The impedance and output are then calculated at the output and impedance calculation device 334. These values can then be displayed on the user interface and display 336. A signal representative of the output and impedance values is received by the controller 338 (which may be a micro processor 338).
[0098]
A control signal is generated by controller 338 that is proportional to the difference between the actual measured value and the desired value. The control signal is used by output circuit 340 to adjust the output by an appropriate amount to maintain the desired output delivered to each first antenna 314 and / or second antenna 316. In a similar manner, the temperature detected at sensor 324 provides feedback to maintain the selected power. The actual temperature is measured at temperature measuring device 342 and this temperature is displayed on the user interface and display 336. A control signal is generated by the controller 338 that is proportional to the difference between the actual measured temperature and the desired temperature. The control signal is used by power circuit 340 to adjust the output by an appropriate amount to maintain the desired temperature delivered to each sensor 324. Multiplexer 346 may be included in many sensors 324 to measure current, voltage, and temperature, and to deliver and distribute energy between first electrode 314 and second electrode 316. . Suitable multiplexers include those manufactured by National Semiconductor (R) Corporation (Santa Clara, Ca.) (e.g., CLC522 and CLC533 series); and Analog Devices (R) Corporation (Norwood, Mass). However, it is not limited to these.
[0099]
The controller 338 can be a digital or analog controller, or it can be a computer with embedded, resident, or otherwise linked software. In one embodiment, the controller 338 may be a Pentium® family micro processing device manufactured by Intel® Corporation (Santa Clara, Ca.). When the controller 338 calculates, it may comprise a CPU coupled through a system bus. The system can include a keyboard, disk drive, or other permanent memory system, display, and other peripheral devices, which are known in the art. Program memory and data memory are also coupled to the bus. In various embodiments, the controller 338 includes an imaging system (ultrasound, CT scanner (including a fast CT scanner such as that manufactured by Imatron® Corporation (South San Francisco, Calif.)), X-rays, MRI, mammography X-rays and the like). In addition, direct visualization and tactile imaging can be used.
[0100]
User interface and display 336 may comprise operator controls and a display. In one embodiment, the user interface 336 can be a PDA device known in the art, such as a Palm® family computer manufactured by Palm® Computing (Santa Clara, Ca.). Interface 336 may be configured to allow a user to input control and processing variables so that appropriate command signals can be generated to the controller. Interface 336 may also receive real-time processing feedback information from one or more sensors 324 and govern the delivery and distribution of energy, fluids, etc. for processing by controller 338.
[0101]
The outputs of current sensor 330 and voltage sensor 332 are used by controller 338 to maintain selected output levels at first antenna 314 and second antenna 316. The amount of RF energy delivered controls the amount of power. The profile of the delivered power can be incorporated into the controller 338 and the set amount of energy to be delivered can also be profiled.
[0102]
Feedback to the circuit, software and controller 338 results in process control and maintenance of the selected output, and (i) the selected output (including RF, microwave, laser, etc.), (ii) duty cycle ( On-off and wattage), (iii) bipolar or monopolar energy delivery, and (iv) infusion medium delivery (including flow rate and pressure). These process variables are controlled and changed based on the temperature monitored by sensor 324, while maintaining the desired delivery of voltage, independent of changes in voltage or current. A controller 338 can be incorporated into the feedback control system 329 to switch the output on and off and adjust the output. Also, with the use of sensor 324 and feedback control system 329, tissue adjacent to RF electrodes 314 and 316 can cause power circuit shutdown to electrode 314 due to excessive electrical impedance generation at electrode 314 or adjacent tissue. Instead, the desired temperature can be maintained over a selected period of time.
[0103]
Here, referring to FIG. 29, current sensor 330 and voltage sensor 332 are connected to the input of analog amplifier 344. Analog amplifier 344 may be a conventional differential amplifier circuit for use with sensor 324. The output of the analog amplifier 344 is continuously connected to the input of the A / D converter 348 by the analog multiplexer 346. The output of the analog amplifier 344 is a voltage representing each sensed temperature. The digitized amplifier output voltage is supplied to the micro processor 350 by the A / D converter 348. The micro processor 350 may be a Power PC (R) commercially available from Motorola or Intel (R) Pentium (R) Series chips. However, it will be appreciated that any suitable microprocessing device or general purpose digital or analog computer may be used to calculate impedance or temperature or to perform image processing and tissue identification functions.
[0104]
Microprocessor 350 continuously receives and stores digital representations of impedance and temperature. Each digital value received by the microprocessor 350 corresponds to a different temperature and impedance. The calculated output and impedance values can be shown in the user interface and display 336. Instead of, or in addition to, a numerical representation of output or impedance, the calculated impedance and output values can be compared by the micro processor 350 to output and impedance limits. If these values exceed a predetermined output value or impedance value, a warning may be given to the user interface and display 336, and the delivery of RF energy may be reduced, altered, or interrupted. A control signal from the microprocessing device 350 can modify the power level supplied to the RF electrodes 314 and 316 by the energy source 320. In a similar manner, the temperature detected by the sensor 324 is (i) tissue hyperthermia; (ii) cell necrosis; and (iii) the extent to which the desired cell necrosis boundary has reached the physical location of the sensor 324 and Provide feedback to determine speed.
[0105]
Referring now to FIG. 30, in one embodiment, in one or more of the impedance determination device 19, power source 20, display device 21 and control system, the controller is incorporated into a single control and display device or unit 20cd. Or can be integrated. Device 20cd may be configured to include one or more of the following displays: impedance profile 19p, tissue site image 4 ′, tumor volume image 4 ″, exfoliation volume image 4av, time temperature profile, tissue identification information, and exfoliation. Setting information (eg, power setting, delivery time, etc.) This device 20cd also overlays the exfoliated volume image 4av on the tumor volume image 4 "or the tissue site image 4 'and places a visual cue 4c in the tumor volume or tissue site Can be configured to overlie the arrangement (including proper and improper arrangements) of the apparatus 10 that includes multiple energy delivery devices. The device 20cd may also include a control knob 20ck for manipulating either the image (4 ', 4 "or 4av) in one or more axes.
[0106]
Referring now to FIG. 31, in various embodiments, the impedance determination device or control system switches from a first mode for measuring impedance to a second mode when a specific system impedance or output condition occurs. Can be configured as follows. In one embodiment, the first mode of measuring impedance is made using the RF treatment output, and then the impedance is calculated using the measured current and voltage described herein. The However, if the system impedance rises significantly and the resulting RF power treatment power level falls below the threshold, the accuracy and precision of the localized impedance determination will depend on the noise of the RF power system. The level decreases as a result of partly due to the decrease in the impedance determining current. This is a problem that is neither recognized nor addressed by current RF stripping / impedance determination devices. Under such conditions, logic resources in the monitoring device may be configured to switch to a second mode for measuring localized impedance. Threshold events that cause mode switching can be selected and include one or more of the following: a decrease in threshold at the treatment (eg, RF) output, an increase in system impedance, a slope of the RF output or system impedance curve (eg, Change in derivative). In various embodiments, the threshold level of the RF treatment output that causes mode switching can be in the range of 1-50 watts, and in certain embodiments, 5 watts, 10 watts, and 25 watts.
[0107]
In the embodiment shown in FIG. 31, an alternative manner of measuring impedance is shown, including superimposing the duty cycle measurement signal 20e on the processing signal 20. The pulse duration 20pd of the signal 20e can range from 1 to 500ms, and in particular embodiments are 50ms, 100ms and 250ms. The duty cycle 20dc of the signal 20e can range from 1 to 99%, and in certain embodiments can be 10%, 25%, 50% and 75%. The monitoring device, power supply or control system may be configured to control the power amplitude of the measurement signal to maintain the selected total signal amplitude 20at. In one embodiment, this total signal amplitude 20 at may range from about 5 to 50 watts, and in certain embodiments may be 10 watts, 20 watts, 30 watts and 40 watts. Also, the duty cycle, pulse duration and total signal amplitude can be controlled to deliver a selectable average power over this duty cycle, which can range from about 0.5 to about 10 watts In this embodiment, it may be 1 watt, 2.5 watt and 5 watt. By controlling the average power delivered over this duty cycle to a higher measurement, the current can have a significant impact on the processing power delivered or the performance of the system, as well as further energy delivery to the target tissue site. Alternatively, it can be used with short pulse durations without causing undesired energy delivery.
[0108]
In use, these and related embodiments of alternative measurements of impedance determination, including overridden duty cycle measurements, benefit from improved accuracy of impedance and signal-to-noise ratio, as well as high system impedance requirements and / or low Provides relevant bioelectrical measurements under a level of delivered RF processing power (ie, peel power).
[0109]
In a related embodiment, the duty cycle and / or pulse duration is configured to change the responsiveness to one or more selected parameters that may include the frequency of the processing signal, the power of the processing signal, or the impedance of the processing signal. Can be done. Changes in either pulse duration or duty cycle can be controlled by the control system and / or the impedance monitoring device using a control method known in the art (eg, PID control) or power supply logic resources. In use, these embodiments continuously tune the impedance determination to changing system conditions to improve the accuracy and accuracy of the impedance and associated bioelectrical measurements.
[0110]
FIG. 32 illustrates a tissue ablation system or device 550, many of which are described above. The apparatus generally comprises a control unit 55, which is designed to operate in the manner described more fully below with respect to FIG. The control unit may control an RF energy source 554 (eg, an energy source of the type described above) to control an energy source (eg, power output) from the energy source to the type of electrode in the multi-electrode stripping device 556. ). The operative connection between the unit 552 and the energy source is indicated at 560, which is any conventional electrical control or machine that the electrical signal from the control unit can be used to change the power output of the power supply 554. Control (eg, servo motor).
[0111]
The output of the energy source is used to change the RF power delivered to the electrode to change the rate of detachment by the device, as described above, when the electrode is deployed to the target tissue as detailed above. Electrically connected to the electrodes of the multi-electrode stripping device.
[0112]
The control unit is also operatively connected to an infusion device 558 (eg, a pump, etc.) and fluid (through a fluid transport tube (shown at 561) supplied to an electrode or other fluid infusion channel in the stripping device. For example, the rate and / or pressure of the saline solution) is controlled. The operative connection between unit 552 and the infusion device is shown at 562 and an electrical signal from the control unit can be used to change the pumping rate or pressure at which fluid is supplied by device 558 to the stripping device. It can be any conventional electrical or mechanical control (eg servo motor).
[0113]
This electrical connection 553 between the stripping device and the control unit is for transmitting an electrical signal relating to the output of the temperature sensor held on the electrode of the stripping device as described above and / or between the electrode and the external body surface. Used to convey current level information regarding current between electrodes (for global impedance measurements) or between electrodes or regions of one electrode (for local impedance measurements). Such impedance and / or temperature measurements may be instantaneous values or values relating to changes in impedance and / or temperature over time.
[0114]
FIG. 33 is a flow diagram illustrating various functions and operations in the control unit when it relates to RF energy source control and injection device control. Initially, the control unit can automatically control the operation of both the energy and the injection device without user intervention, or to optimize the ablation procedure, especially for burnt attachments to nearly healthy tissue Information may be provided to the user indicating how the user should control the operating level of one or both of the energy device and the injection device to ensure complete tissue ablation while minimizing general damage.
[0115]
Initially, the user may enter a target tissue type (eg, liver tumor, bone tumor, etc.) as shown at 564. The control unit preferably controls tissue impedance characteristics, and / or changes in healing rate and impedance of a particular tissue type, when a predetermined power level is applied, preferably in the presence of an implant. save. This internal data indicates that the tissue on which the electrodes of the ablation device are deployed is the desired tissue type based on impedance and / or temperature changes detected during the initial operation of the system, as shown below. Used to confirm that.
[0116]
When the user is ready to insert the device into the patient, deploy an electrode in the target tissue, and define a selected volume for tissue ablation, the system is activated to allow fluid to pass through the device. The energy device is controlled (indicated at 566) to initiate injection and also deliver low power pulsed RF energy to the deployed electrode. This low power pulse is used to generate an overall or local current value and measure the overall or local impedance value when the electrode is deployed as shown at 568 and 570. The The power applied to the electrodes during deployment may also be sufficient to heat the electrodes very locally and facilitate the entry of the electrodes into the target tissue. The ablation device may also signal to the control unit through connection 553 (FIG. 33) when a selected degree of electrode deployment corresponding to the desired tissue volume has been achieved.
[0117]
The impedance (and / or temperature) measurements taken during the deployment of the electrode can be compared to the tissue-specific impedance or temperature stored in the control unit, and the tissue on which the electrode is deployed is actually selected. Confirmed to be a target tissue. If the program finds a discrepancy, such as 574, the control unit may signal the user to redeploy this electrode, as shown. If tissue verification is performed, the program that instructs the user to initiate the ablation procedure, or the power level delivered by the energy source is advanced to the desired level, and as indicated, as indicated at 576, A program proceeds that automatically initiates the exfoliation phase of this operation by increasing the rate of fluid injection into the tissue.
[0118]
Once the exfoliation operation proceeds, the system performs continuous and periodic impedance and / or temperature measurements at the target tissue site and, as indicated at 570, automatically or at power level and / or infusion rate. User controlled adjustments are performed to achieve the desired rate and degree of stripping. As described above, if this adjustment is made automatically, the control unit operates to automatically adjust the power level and / or infusion rate of the devices 554, 562, respectively (FIG. 32). Alternatively, the control unit may have a display for indicating the direction and degree of adjustment requirements and the control to the user to make this adjustment.
[0119]
Throughout the adjustment period, the control unit receives periodic and repeated impedance and / or temperature data that are processed to guide control of the energy and injection device. Data processing operations are shown at the bottom of FIG. Initially, as shown at 580, the program asks whether the temperature has risen appropriately (coinciding with the objective of optimal tissue ablation, the ablation can be completed within the shortest possible time. As desired). If the rate of temperature increase is below a selected threshold, the control unit is activated (or directed to the user) to adjust the power and / or the rate of infusion into the tissue, for example to increase the power Or promote healing speed by reducing infusion. The program also queries whether the measured impedance is above the desired threshold, as at 582. If the measured impedance is too low, the program again operates (or instructs the user) to adjust the power delivery to the electrode and / or the rate of electrolyte injection into the tissue. This procedure is repeated until both the temperature change and the impedance level are within the selected tolerance.
[0120]
The program also looks for impedance spikes that are indicators of scorching or overheating. If these are observed by theoretical decision 584, the control unit operates to adjust (or instruct the user to adjust) either power level or injection rate to reduce impedance spikes. Minimize.
[0121]
Assuming that all of these variables are within acceptable levels, the system will maximize the ablation process, i.e., tissue scorching (or excessive tissue scoring) will also cause exfoliation damage to adjacent healthy tissue. Is adjusted appropriately to achieve delamination near the maximum speed at which As indicated at 586, the program then monitors when complete stripping has been achieved in the area of the electrode. If delamination is incomplete, the program can continue with the existing power and / or injection rate level, or adjust this level appropriately.
[0122]
If complete local ablation has been achieved, the system can query whether detachment of the entire target area has been achieved, as in 558. If complete stripping is achieved, the operation of the program is terminated and the system can terminate or reduce power to a lower power / injection level. For example, some RF power is applied to the electrode during electrode containment or catheter containment to reduce the risk of exposing healthy tissue to tumor cells during removal of the ablation device from the patient. To do.
[0123]
If the total ablation is incomplete, the system signals the user to proceed with electrode deployment and the above ablation process is repeated until a final target tissue ablation is achieved.
[0124]
(Conclusion)
It is understood that Applicants have provided new and useful devices and methods for tumor diagnosis and treatment using minimally invasive methods including tissue impedance measurements. The foregoing description of various embodiments of the present invention has been presented for purposes of illustration and description. This is not intended to be exhaustive or to limit the invention to the precise form disclosed. Embodiments of the present invention can be configured for the treatment of tumors and tissue masses at or below the tissue surface of a number of organs including but not limited to liver, breast, bone and lung. However, embodiments of the present invention are equally applicable to other organs and tissues. Obviously, many modifications and variations will be apparent to practitioners skilled in this art. Further, elements from one embodiment can be easily combined with elements from one or more other embodiments. Such a combination may form a number of embodiments within the scope of the present invention. It is intended that the scope of the invention be defined by the claims appended hereto and their equivalents.
[Brief description of the drawings]
[0125]
FIG. 1 is a side view showing the placement at an tissue site of an embodiment of an apparatus for detecting and treating a tumor using a localized impedance determination method.
FIG. 2 is a side view showing components of an apparatus for detecting and treating a tumor using impedance determination, the apparatus comprising an elongate delivery device, a sensor array, a sensor, an electrode, An energy delivery device and an advancement member are provided.
FIG. 3a is a schematic illustration of an embodiment of an impedance sensor array configured to determine the impedance of a tissue volume by a plurality of selectable conductive paths.
FIG. 3b is a schematic diagram illustrating an embodiment of the apparatus showing the use of primary and secondary conductive paths and conductive path angles.
Figures 4a-c are perspective views showing various arrangements of emission and detection members; Figure 4a shows an embodiment centered on a return electrode surrounded by other electrodes; Shows an embodiment with a return electrode arranged eccentric with respect to the other electrodes; FIG. 4c shows an embodiment with a plurality of independently positionable impedance sensor arrays.
FIG. 5 illustrates a plurality of groups of conductive paths for sampling a plurality of tissue volumes and for determining an impedance vector and impedance location for each sample volume in an embodiment of the present invention. It is a perspective view which shows use.
FIG. 6 is a perspective view illustrating an embodiment of an apparatus for detecting and treating a tumor, the apparatus comprising a software module for analyzing impedance data and generating impedance profiles and images. An impedance monitoring device having a memory resource and a logic source is provided.
FIG. 7A is a plot of a tissue impedance curve showing the frequency dependence of impedance.
FIG. 7B is a plot of a tissue composite impedance curve showing the frequency dependence of the composite impedance.
FIG. 8A is a plot of an impedance curve showing the use of multiple frequency impedance curves to monitor the time course of debonding.
FIG. 8B is a plot of an impedance curve showing the use of multiple frequency impedance curves to monitor the time course of debonding.
FIG. 8C is a plot of an impedance curve illustrating the use of multiple frequency impedance curves to monitor the time course of debonding.
FIG. 8D is an impedance curve plot illustrating the use of multiple frequency impedance curves to monitor the time course of debonding.
FIG. 8E is a plot of a composite impedance curve (imaginary value vs. real value) showing the use of a composite impedance curve to monitor the time course of debonding.
FIG. 8F is a plot of a composite impedance curve (imaginary value vs. real value) showing the use of a composite impedance curve to monitor the time course of debonding.
FIG. 8G is a plot of a composite impedance curve (imaginary value vs. real value) showing the use of a composite impedance curve to monitor the time course of delamination.
FIG. 9A is a plot of a composite impedance curve showing the use of the composite impedance curve to identify tissue type or tissue condition.
FIG. 9B is a plot of a composite impedance curve showing the use of the composite impedance curve to identify tissue type or tissue condition.
FIG. 9C is a plot of a composite impedance curve showing the use of the composite impedance curve to identify tissue type or tissue condition.
FIG. 10 is a plot of spectral signal intensity versus time for a sample volume of exfoliated tissue showing quantitative determinants of the exfoliation endpoint.
FIG. 11 is a perspective view showing a three-dimensional plot of composite impedance.
FIG. 12a is a side view showing an embodiment of an introducer.
FIG. 12b is a cross-sectional view showing the cross-sectional area profile of the introducer.
FIG. 12c is a cross-sectional view showing the cross-sectional area profile of the introducer.
FIG. 13 is a side view of an embodiment of an introducer that can be deflected with the introducer components.
FIG. 14 is a side view illustrating an embodiment of a tissue biopsy and treatment apparatus comprising a handpiece and coupled to a suction device, a fluid delivery device, and a fluid reservoir.
FIGS. 15a-15h are side views showing various arrangements of electrodes, including ring-like, sphere, hemispherical, cylindrical, conical, and needle-like.
FIG. 16 is a side view and shows an embodiment of a needle electrode positioned to penetrate tissue.
FIG. 17 is a side view showing an embodiment of an electrode having at least one radius of curvature.
FIG. 18 is a side view and shows an embodiment of an electrode having at least one radius of curvature, a sensor and a coupled advance device.
FIG. 19 is a perspective view illustrating an embodiment of an electrode for defining an electrode or impedance sensor length or energy delivery surface with an insulating sleeve positioned on the outer surface of the elastic member.
FIG. 20 is a perspective view showing an embodiment of an electrode comprising a plurality of insulating sleeves that insulate around selected sections of the electrode.
FIG. 21 is a perspective view of an embodiment of an electrode with an insulation extending along a longitudinal section of the electrode and defining an adjacent longitudinal energy delivery surface.
FIG. 22 is a cross-sectional view of the embodiment of FIG.
FIG. 23a is an embodiment of an apparatus comprising an electrode having lumens and apertures arranged for fluid delivery and use of infusion fluid to create a reinforced electrode; It is a side view.
FIG. 23b is a perspective view showing the key components of the tissue stripping device including the placement of an injection device with multiple syringes and multi-channel tubing.
FIG. 23c is an exploded view of the distal portion of the apparatus of the embodiment of FIG. 23b showing its distal tip components and the conductive path of the device for measuring and adjusting impedance.
FIG. 23d shows a plot of dissipated power against impedance, illustrating a novel approach for maximizing ablative power delivery at a target tissue site at a non-minimum impedance.
FIG. 23e shows a plot of tissue resistance versus distance from an electrode embodiment, which illustrates the use of injection to reduce adjacent tissue burns.
FIG. 24 is a perspective view illustrating an embodiment of an impedance sensing member comprising a conductive coating, which can be arranged to create an impedance gradient within the sensing member.
FIGS. 25a-25c are perspective views of an embodiment of an energy delivery debonding device using a frequency controlled positionable debonding field. FIGS.
Figures 26a-26c are plots of energy density or concentration versus horizontal distance from the electrode / energy delivery device of the embodiment of Figures 25a-25c.
Figures 26a-26c are plots of energy density or concentration versus horizontal distance from the electrode / energy delivery device of the embodiment of Figures 25a-25c.
Figures 26a-26c are plots of energy density or concentration versus horizontal distance from the electrode / energy delivery device of the embodiment of Figures 25a-25c.
FIG. 27 is a flowchart illustrating a method for generating and displaying an image derived from impedance.
FIG. 28 is a block diagram illustrating a controller, power supply, output circuit, and other electronics components used with an embodiment of a control system of another embodiment of the present invention.
FIG. 29 is a block diagram illustrating an analog amplifier, a multiplexer, and a microprocessor (microprocessor) used with one embodiment of a control system or another embodiment of the present invention. .
FIG. 30 is a side view showing a control unit and a display unit (display unit) used in various embodiments of the present invention.
FIG. 31 is a plot illustrating an embodiment of an impedance determination duty cycle signal that is super-impossible for an RF processing signal under selectable threshold conditions.
FIG. 32 illustrates an embodiment of a device for impedance adjustment using injection.
FIG. 33 is a flow chart illustrating the use of one embodiment of the device.

Claims (23)

A cell necrosis device for use in exfoliating a target tissue, in operable conditions, as follows:
An elongate delivery device comprising a lumen;
An energy delivery device comprising a plurality of electrodes, each electrode having a tissue piercing distal portion and capable of being placed in the elongate delivery device in a miniaturized state and having a curved shape when deployed. Pre-formed so that the plurality of electrodes exhibit a changing direction of movement when advanced from the elongate delivery device to a selected tissue site and are peeled when in the deployed state An energy delivery device defining a volume;
An RF energy source connected to the energy delivery device;
A fluid delivery device operably connected to at least one of the elongate delivery device or the energy delivery device, wherein fluid is passed through the fluid delivery device to the at least one introduction port and into the target tissue. A fluid delivery device for delivery;
A control unit, (I) connected to the RF energy source to control RF energy delivery to the energy delivery device, and (ii) the energy for use in detecting impedance A control unit connected to the delivery device; and a controller for the fluid delivery device, wherein the amount of fluid introduced from the device into the target tissue is detected by the controller. A control device, which can be controlled in response to a certain impedance,
With
At least one of (i) the elongate delivery device or (ii) at least one of the plurality of electrodes is passed through the at least one, (i) the elongate delivery device or (ii) at least one of the plurality of electrodes. Adapted for fluid delivery to at least one inlet port disposed on at least one of the
apparatus. The apparatus of claim 1, wherein the control unit is operatively connected to at least one of the plurality of electrodes to determine tissue impedance. The local impedance is directly determined by determining the impedance along a conductive path between one or more sites in at least one of the plurality of electrodes. The device described. The apparatus of claim 3, wherein the one or more sites are at least two sites on the same electrode for determining local impedance over a distance. The apparatus according to claim 1, wherein at least one of the plurality of electrodes is an active electrode, and the control unit is operatively connected to the active electrode. The apparatus of any one of claims 1-5, further comprising a temperature sensor disposed on at least one of the plurality of electrodes and operably connected to the control unit. The control unit is operatively connected to the fluid delivery device to adjust the amount of fluid introduced from the fluid delivery device in response to the detected impedance. The apparatus of any one of these. 8. The control unit of any one of claims 1-7, wherein the control unit is manually adjustable to adjust the amount of energy delivered to the at least one electrode in response to the detected impedance. The device described. 9. The controller of any one of claims 1-8, wherein the controller is manually adjustable to adjust the amount of fluid introduced from the fluid delivery device in response to the detected impedance. Equipment. The apparatus according to any one of the preceding claims, wherein each of at least two of the plurality of electrodes comprises a separate introduction lumen for delivering fluid. The apparatus of claim 10, wherein the controller for the fluid delivery device is operable to provide independent control of introduction through the separate introduction lumen. A method for use in exfoliating a target tissue in a patient, comprising:
Placing an RF delivery device, the RF delivery device comprising:
(A) an elongate delivery device comprising a lumen;
(B) a plurality of RF electrodes comprising a tissue perforation distal end, wherein the RF electrodes can be placed in the introducer in a miniaturized state and pre-shaped to exhibit a curved shape when deployed. The plurality of RF electrodes exhibit a changing direction of movement when advanced from the introducer to a selected target tissue, wherein at least one of the plurality of electrodes has the at least one An RF electrode adapted for fluid delivery through the one to at least one introduction port;
(C) a fluid delivery device operably connected to at least one of the elongate delivery device or the plurality of electrodes for delivering fluid through the fluid delivery device to the at least one introduction port; Of fluid delivery devices,
(D) a control unit operably connected to at least one of the plurality of electrodes for use in detecting impedance; and (e) a controller for the fluid delivery device;
The positioning step is effective for positioning the distal end of the catheter within or adjacent to the target tissue,
Deploying the electrode to define a delamination volume comprising at least a portion of the target tissue;
Introducing a fluid through the electrode into the defined exfoliation volume;
Applying a stripping RF current to the electrode, comprising:
Peeling the target tissue contained within the defined volume by the applying step;
Determining the impedance and adjusting the impedance by controlling the amount of fluid introduced from the RF delivery device;
Including the method. The method of claim 12, wherein the introducing step is performed one or more before, during and after the peeling step. 14. A method according to claim 12 or 13, wherein the step of adjusting comprises changing flow rates at different electrodes of the plurality of electrodes. The method according to claim 12, wherein the peeling step is further performed during the developing step. The introduced fluid is an introduced electrolyte solution, and the method changes the conductivity of the introduced solution by controlling the concentration of the electrolyte in the introduced electrolyte solution; 16. A method according to any one of claims 12 to 15, further comprising. 17. The method of claim 16, wherein the introduced electrolyte solution is a saline solution and the conductivity of the introduced electrolyte solution is controlled by changing the salt content of the solution. 18. A method according to claim 16 or 17, wherein the introducing step is effective to control a zone of introduction around individual electrodes of the plurality of electrodes. The impedance is a systemic impedance or a local impedance, the systemic impedance being determined from the impedance between one or more electrodes and the outside of the patient, and for the local impedance between the electrodes or The method according to any one of claims 12 to 18, wherein the method is determined from impedance between two or more sites on the same electrode. 20. The method of claim 19, further comprising the step of maximizing power dissipation efficiency by controlling systemic impedance and / or local impedance to an optimal value. 20. The method of claim 19, wherein controlling the impedance is controlling the impedance between a minimum value and a maximum value. 20. The method of claim 19, wherein the introducing step is performed with a pre-programmed flow rate profile to produce a time-varying impedance profile. 23. The method of any of claims 12-22, wherein the step of determining impedance is performed at a frequency selected from the group consisting of the same frequency as the energy source, a frequency different from the energy source, and a range of frequencies. 2. The method according to item 1.

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